| 1973-04-06 | vs PHI | 1 | W 3-0 | 1-0 | 2 | 27,326 | Tom Seaver | Steve Carlton | Tom Seaver | Steve Carlton | Tug McGraw | 3 | 0 | 3 |
| 1973-04-07 | vs PHI | 2 | W 3-2 | 2-0 | 2 | 18,738 | Jon Matlack | Jim Lonborg | Jon Matlack | Dick Selma | | 6 | 2 | 4 |
| 1973-04-11 | @ SLN | 3 | W 5-4 | 3-0 | 1 | 12,290 | Jerry Koosman | Reggie Cleveland | Jerry Koosman | Reggie Cleveland | Phil Hennigan | 11 | 6 | 5 |
| 1973-04-12 | @ SLN | 4 | W 2-1 | 4-0 | 1 | 6,356 | Tom Seaver | Bob Gibson | Tom Seaver | Bob Gibson | Phil Hennigan | 13 | 7 | 6 |
| 1973-04-13 | @ PHI | 5 | L 1-7 | 4-1 | 2 | 7,127 | Jon Matlack | Larry Christenson | Larry Christenson | Jon Matlack | | 14 | 14 | 0 |
| 1973-04-14 | @ PHI | 6 | L 3-7 | 4-2 | 2 | 11,063 | Jim McAndrew | Steve Carlton | Steve Carlton | Jim McAndrew | | 17 | 21 | -4 |
| 1973-04-15 | @ PHI | 7 | W 2-1 | 5-2 | 2 | 30,718 | Harry Parker | Jim Lonborg | Harry Parker | Jim Lonborg | Tug McGraw | 19 | 22 | -3 |
| 1973-04-17 | vs CHN | 8 | L 0-1 | 5-3 | 3 | 14,549 | Tom Seaver | Fergie Jenkins | Fergie Jenkins | Tom Seaver | | 19 | 23 | -4 |
| 1973-04-18 | vs CHN | 9 | L 0-1 | 5-4 | 3 | 14,874 | Jon Matlack | Ray Burris | Ray Burris | Jon Matlack | Jack Aker | 19 | 24 | -5 |
| 1973-04-19 | vs CHN | 10 | W 3-1 | 6-5 | 3 | 0 | Jerry Koosman | Rick Reuschel | Jerry Koosman | Rick Reuschel | | 22 | 25 | -3 |
| 1973-04-19 | vs CHN | 11 | L 0-7 | 6-5 | 3 | 38,079 | Jim McAndrew | Burt Hooton | Burt Hooton | Jim McAndrew | | 22 | 32 | -10 |
| 1973-04-21 | vs MON | 12 | W 5-0 | 7-5 | 3 | 40,011 | Harry Parker | Balor Moore | Harry Parker | Balor Moore | Tug McGraw | 27 | 32 | -5 |
| 1973-04-22 | vs MON | 13 | L 1-2 | 8-6 | 3 | 0 | Tom Seaver | John Strohmayer | Mike Marshall | Phil Hennigan | Tom Walker | 28 | 34 | -6 |
| 1973-04-22 | vs MON | 14 | W 13-3 | 8-6 | 3 | 27,230 | Jim McAndrew | Steve Renko | Jim McAndrew | Steve Renko | George Stone | 41 | 37 | 4 |
| 1973-04-24 | @ HOU | 15 | L 2-4 | 8-7 | 3 | 12,759 | Jon Matlack | Ken Forsch | Ken Forsch | Jon Matlack | Jim Ray | 43 | 41 | 2 |
| 1973-04-25 | @ HOU | 16 | W 5-2 | 9-7 | 3 | 15,248 | Jerry Koosman | Don Wilson | Jerry Koosman | Don Wilson | | 48 | 43 | 5 |
| 1973-04-26 | @ HOU | 17 | W 2-1 | 10-7 | 2 | 12,295 | Jim McAndrew | Jerry Reuss | Jim McAndrew | Jerry Reuss | Tug McGraw | 50 | 44 | 6 |
| 1973-04-27 | @ ATL | 18 | L 0-2 | 10-8 | 3 | 7,527 | Tom Seaver | Pat Dobson | Pat Dobson | Tom Seaver | | 50 | 46 | 4 |
| 1973-04-28 | @ ATL | 19 | W 4-2 | 11-8 | 3 | 9,752 | Jon Matlack | Ron Reed | Jon Matlack | Ron Reed | Tug McGraw | 54 | 48 | 6 |
| 1973-04-29 | @ ATL | 20 | W 1-0 | 12-8 | 2 | 12,152 | Jerry Koosman | Carl Morton | Jerry Koosman | Carl Morton | | 55 | 48 | 7 |
| 1973-05-02 | vs CIN | 21 | L 1-6 | 12-9 | 2 | 19,163 | Tom Seaver | Ross Grimsley | Ross Grimsley | Tom Seaver | Pedro Borbon | 56 | 54 | 2 |
| 1973-05-03 | vs CIN | 22 | L 5-6 | 12-10 | 3 | 9,163 | Jon Matlack | Jim McGlothlin | Tom Hall | Jon Matlack | | 61 | 60 | 1 |
| 1973-05-04 | vs HOU | 23 | L 5-9 | 12-11 | 3 | 17,397 | Jerry Koosman | Ken Forsch | Jim Ray | Phil Hennigan | Fred Gladding | 66 | 69 | -3 |
| 1973-05-05 | vs HOU | 24 | L 2-9 | 12-12 | 4 | 14,178 | Jim McAndrew | Don Wilson | Don Wilson | Jim McAndrew | | 68 | 78 | -10 |
| 1973-05-06 | vs HOU | 25 | L 8-14 | 12-13 | 3 | 22,594 | Harry Parker | Jerry Reuss | Mike Cosgrove | Tug McGraw | Jim Crawford | 76 | 92 | -16 |
| 1973-05-07 | vs ATL | 26 | W 7-2 | 13-13 | 3 | 11,729 | Tom Seaver | Pat Dobson | Tom Seaver | Pat Dobson | | 83 | 94 | -11 |
| 1973-05-08 | vs ATL | 27 | L 6-10 | 13-14 | 3 | 6,840 | Jon Matlack | Ron Reed | Ron Reed | Jon Matlack | Roric Harrison | 89 | 104 | -15 |
| 1973-05-09 | vs ATL | 28 | W 8-1 | 14-14 | 2 | 8,125 | Jerry Koosman | Carl Morton | Jerry Koosman | Carl Morton | | 97 | 105 | -8 |
| 1973-05-11 | @ PIT | 29 | W 4-3 | 15-14 | 2 | 17,564 | Harry Parker | Dock Ellis | Harry Parker | Dock Ellis | Tug McGraw | 101 | 108 | -7 |
| 1973-05-12 | @ PIT | 30 | W 6-0 | 16-14 | 2 | 13,058 | Tom Seaver | Bob Moose | Tom Seaver | Bob Moose | | 107 | 108 | -1 |
| 1973-05-13 | @ PIT | 31 | W 6-4 | 17-14 | 2 | 14,310 | Jim McAndrew | Luke Walker | Jim McAndrew | Luke Walker | Tug McGraw | 113 | 112 | 1 |
| 1973-05-15 | @ CHN | 32 | L 3-4 | 17-15 | 2 | 11,517 | Jerry Koosman | Burt Hooton | Burt Hooton | Jerry Koosman | Jack Aker | 116 | 116 | 0 |
| 1973-05-16 | @ MON | 33 | W 8-3 | 18-15 | 2 | 10,023 | Harry Parker | Mike Torrez | Harry Parker | Mike Torrez | Tug McGraw | 124 | 119 | 5 |
| 1973-05-18 | vs PIT | 34 | W 4-3 | 19-15 | 2 | 34,565 | Tom Seaver | Luke Walker | Tom Seaver | Luke Walker | | 128 | 122 | 6 |
| 1973-05-19 | vs PIT | 35 | L 1-4 | 19-16 | 2 | 32,622 | Jon Matlack | Nelson Briles | Dave Giusti | Tug McGraw | | 129 | 126 | 3 |
| 1973-05-22 | vs SLN | 36 | L 3-5 | 19-17 | 2 | 17,425 | Jerry Koosman | Rick Wise | Rick Wise | Jerry Koosman | Diego Segui | 132 | 131 | 1 |
| 1973-05-24 | @ LAN | 37 | W 7-3 | 20-17 | 2 | 27,580 | Tom Seaver | Tommy John | George Stone | Doug Rau | Jim McAndrew | 139 | 134 | 5 |
| 1973-05-25 | @ LAN | 38 | L 4-6 | 20-18 | 2 | 53,624 | Jon Matlack | Claude Osteen | Claude Osteen | Jon Matlack | Pete Richert | 143 | 140 | 3 |
| 1973-05-26 | @ LAN | 39 | L 5-9 | 20-19 | 2 | 28,635 | Harry Parker | Al Downing | George Culver | Jim McAndrew | Pete Richert | 148 | 149 | -1 |
| 1973-05-27 | @ LAN | 40 | L 1-2 | 20-20 | 2 | 31,108 | Jerry Koosman | Don Sutton | Don Sutton | Jerry Koosman | | 149 | 151 | -2 |
| 1973-05-28 | @ SFN | 41 | L 5-6 | 20-21 | 2 | 18,101 | Tommy Moore | Juan Marichal | Juan Marichal | Tommy Moore | Elias Sosa | 154 | 157 | -3 |
| 1973-05-29 | @ SFN | 42 | W 5-2 | 21-21 | 2 | 7,289 | Tom Seaver | Jim Barr | Tom Seaver | Randy Moffitt | | 159 | 159 | 0 |
| 1973-05-30 | @ SFN | 43 | L 2-3 | 21-22 | 2 | 5,296 | Jon Matlack | Tom Bradley | Tom Bradley | Jon Matlack | Sam McDowell | 161 | 162 | -1 |
| 1973-06-01 | @ SDN | 44 | L 0-4 | 21-23 | 3 | 6,394 | Jerry Koosman | Bill Greif | Bill Greif | Jerry Koosman | | 161 | 166 | -5 |
| 1973-06-02 | @ SDN | 45 | L 0-3 | 21-24 | 3 | 7,376 | George Stone | Clay Kirby | Clay Kirby | George Stone | | 161 | 169 | -8 |
| 1973-06-03 | @ SDN | 46 | W 9-2 | 22-24 | 3 | 9,665 | Tom Seaver | Mike Caldwell | Tom Seaver | Mike Caldwell | | 170 | 171 | -1 |
| 1973-06-04 | @ CIN | 47 | L 0-5 | 22-25 | 4 | 13,145 | Jon Matlack | Jack Billingham | Jack Billingham | Jon Matlack | | 170 | 176 | -6 |
| 1973-06-05 | @ CIN | 48 | L 5-6 | 22-26 | 5 | 14,654 | Jerry Koosman | Ross Grimsley | Don Gullett | Phil Hennigan | | 175 | 182 | -7 |
| 1973-06-08 | vs LAN | 49 | L 3-5 | 22-27 | 5 | 42,500 | Tom Seaver | Tommy John | Tommy John | Tom Seaver | Pete Richert | 178 | 187 | -9 |
| 1973-06-09 | vs LAN | 50 | W 4-2 | 23-27 | 5 | 47,800 | Jon Matlack | Al Downing | Jon Matlack | Al Downing | | 182 | 189 | -7 |
| 1973-06-10 | vs LAN | 51 | L 0-4 | 23-28 | 5 | 41,139 | Jerry Koosman | Claude Osteen | Claude Osteen | Jerry Koosman | | 182 | 193 | -11 |
| 1973-06-11 | vs SFN | 52 | L 1-2 | 23-29 | 5 | 29,160 | George Stone | Ron Bryant | Ron Bryant | George Stone | Randy Moffitt | 183 | 195 | -12 |
| 1973-06-12 | vs SFN | 53 | W 5-4 | 24-29 | 4 | 24,135 | Jim McAndrew | Juan Marichal | Harry Parker | Juan Marichal | Phil Hennigan | 188 | 199 | -11 |
| 1973-06-13 | vs SFN | 54 | W 3-1 | 25-29 | 4 | 25,776 | Tom Seaver | Tom Bradley | Tom Seaver | Tom Bradley | | 191 | 200 | -9 |
| 1973-06-15 | vs SDN | 55 | W 5-2 | 26-29 | 4 | 27,524 | Jon Matlack | Steve Arlin | Jon Matlack | Steve Arlin | | 196 | 202 | -6 |
| 1973-06-16 | vs SDN | 56 | W 10-2 | 27-29 | 4 | 24,452 | Jerry Koosman | Mike Caldwell | Jerry Koosman | Mike Caldwell | | 206 | 204 | 2 |
| 1973-06-17 | vs SDN | 57 | W 3-1 | 28-29 | 3 | 32,641 | George Stone | Bill Greif | George Stone | Bill Greif | Tug McGraw | 209 | 205 | 4 |
| 1973-06-18 | @ PHI | 58 | L 6-9 | 28-30 | 4 | 13,190 | Jim McAndrew | Ken Brett | Ken Brett | Jim McAndrew | | 215 | 214 | 1 |
| 1973-06-19 | @ PHI | 59 | L 1-6 | 28-31 | 4 | 17,481 | Harry Parker | Jim Lonborg | Jim Lonborg | Harry Parker | Mac Scarce | 216 | 220 | -4 |
| 1973-06-20 | @ PHI | 60 | L 3-4 | 28-32 | 4 | 24,302 | Jon Matlack | Wayne Twitchell | Wayne Twitchell | Jon Matlack | | 219 | 224 | -5 |
| 1973-06-21 | @ PIT | 61 | L 1-2 | 28-33 | 4 | 10,099 | Jerry Koosman | Luke Walker | Luke Walker | Buzz Capra | | 220 | 226 | -6 |
| 1973-06-22 | @ PIT | 62 | W 5-4 | 29-33 | 4 | 21,129 | George Stone | Steve Blass | George Stone | Steve Blass | | 225 | 230 | -5 |
| 1973-06-23 | @ PIT | 63 | L 2-3 | 29-34 | 4 | 24,337 | Jim McAndrew | Dock Ellis | Ramon Hernandez | Phil Hennigan | | 227 | 233 | -6 |
| 1973-06-24 | @ PIT | 64 | W 5-2 | 30-34 | 4 | 20,984 | Tom Seaver | Bob Moose | Tom Seaver | Bob Moose | | 232 | 235 | -3 |
| 1973-06-25 | vs CHN | 65 | L 2-3 | 30-35 | 5 | 31,984 | Jon Matlack | Rick Reuschel | Dave LaRoche | Jon Matlack | Bill Bonham | 234 | 238 | -4 |
| 1973-06-26 | vs CHN | 66 | L 1-5 | 30-36 | 5 | 18,861 | Jerry Koosman | Burt Hooton | Burt Hooton | Jerry Koosman | | 235 | 243 | -8 |
| 1973-06-27 | vs PHI | 67 | W 7-6 | 31-37 | 5 | 0 | George Stone | Barry Lersch | George Stone | Barry Lersch | Buzz Capra | 242 | 249 | -7 |
| 1973-06-27 | vs PHI | 68 | L 1-7 | 31-37 | 5 | 31,095 | Harry Parker | Mike Wallace | Mike Wallace | Harry Parker | | 243 | 256 | -13 |
| 1973-06-28 | vs PHI | 69 | L 4-11 | 31-38 | 6 | 9,965 | Jim McAndrew | Jim Lonborg | Jim Lonborg | Jim McAndrew | | 247 | 267 | -20 |
| 1973-06-29 | @ CHN | 70 | L 3-4 | 31-39 | 6 | 22,293 | Tom Seaver | Rick Reuschel | Dave LaRoche | Buzz Capra | | 250 | 271 | -21 |
| 1973-06-30 | @ CHN | 71 | W 2-1 | 32-39 | 6 | 29,512 | Jon Matlack | Burt Hooton | Jon Matlack | Burt Hooton | | 252 | 272 | -20 |
| 1973-07-01 | @ CHN | 72 | W 6-5 | 33-40 | 6 | 0 | Jerry Koosman | Fergie Jenkins | Jerry Koosman | Fergie Jenkins | Tug McGraw | 258 | 277 | -19 |
| 1973-07-01 | @ CHN | 73 | L 5-6 | 33-40 | 6 | 42,497 | Harry Parker | Larry Gura | Jack Aker | Tug McGraw | | 263 | 283 | -20 |
| 1973-07-02 | @ MON | 74 | L 1-2 | 33-41 | 6 | 14,618 | George Stone | Steve Renko | Steve Renko | Buzz Capra | | 264 | 285 | -21 |
| 1973-07-03 | @ MON | 75 | L 8-19 | 33-42 | 6 | 12,279 | Jim McAndrew | Ernie McAnally | Ernie McAnally | Jim McAndrew | Mike Marshall | 272 | 304 | -32 |
| 1973-07-04 | @ MON | 76 | L 5-7 | 33-43 | 6 | 15,801 | Tom Seaver | Balor Moore | Joe Gilbert | Buzz Capra | Mike Marshall | 277 | 311 | -34 |
| 1973-07-05 | @ MON | 77 | W 7-3 | 34-43 | 6 | 15,628 | Jon Matlack | Bill Stoneman | Jon Matlack | Mickey Scott | Tug McGraw | 284 | 314 | -30 |
| 1973-07-06 | vs ATL | 78 | L 0-2 | 34-44 | 6 | 37,266 | Jerry Koosman | Ron Schueler | Ron Schueler | Jerry Koosman | | 284 | 316 | -32 |
| 1973-07-07 | vs ATL | 79 | L 8-9 | 34-45 | 6 | 30,468 | Ray Sadecki | Carl Morton | Joe Hoerner | Tug McGraw | Adrian Devine | 292 | 325 | -33 |
| 1973-07-08 | vs ATL | 80 | L 2-4 | 34-46 | 6 | 33,017 | George Stone | Phil Niekro | Phil Niekro | George Stone | | 294 | 329 | -35 |
| 1973-07-09 | vs HOU | 81 | W 2-1 | 35-46 | 6 | 19,099 | Tom Seaver | Don Wilson | Harry Parker | Jim York | | 296 | 330 | -34 |
| 1973-07-10 | vs HOU | 82 | W 1-0 | 36-46 | 6 | 19,942 | Jon Matlack | Jerry Reuss | Jon Matlack | Jerry Reuss | | 297 | 330 | -33 |
| 1973-07-11 | vs HOU | 83 | L 1-7 | 36-47 | 6 | 18,776 | Jerry Koosman | Dave Roberts | Dave Roberts | Jerry Koosman | | 298 | 337 | -39 |
| 1973-07-13 | @ CIN | 84 | L 1-2 | 37-48 | 6 | 0 | Tom Seaver | Jack Billingham | Jack Billingham | Tom Seaver | | 299 | 339 | -40 |
| 1973-07-13 | @ CIN | 85 | W 7-5 | 37-48 | 6 | 40,283 | Ray Sadecki | Jim McGlothlin | Ray Sadecki | Jim McGlothlin | Harry Parker | 306 | 344 | -38 |
| 1973-07-14 | @ CIN | 86 | W 5-2 | 38-48 | 6 | 36,166 | George Stone | Tom Hall | George Stone | Don Gullett | Buzz Capra | 311 | 346 | -35 |
| 1973-07-15 | @ CIN | 87 | L 1-3 | 38-49 | 6 | 35,121 | Jon Matlack | Ross Grimsley | Ross Grimsley | Jon Matlack | | 312 | 349 | -37 |
| 1973-07-16 | @ ATL | 88 | L 6-8 | 38-50 | 6 | 7,688 | Jerry Koosman | Phil Niekro | Jim Panther | Jerry Koosman | Jimmy Freeman | 318 | 357 | -39 |
| 1973-07-17 | @ ATL | 89 | W 8-7 | 39-50 | 6 | 8,161 | Tug McGraw | Carl Morton | Buzz Capra | Adrian Devine | Harry Parker | 326 | 364 | -38 |
| 1973-07-18 | @ ATL | 90 | W 12-2 | 40-50 | 6 | 10,548 | Tom Seaver | Roric Harrison | Tom Seaver | Roric Harrison | | 338 | 366 | -28 |
| 1973-07-20 | @ HOU | 91 | L 2-6 | 40-51 | 6 | 20,731 | Jon Matlack | Dave Roberts | Dave Roberts | Jon Matlack | | 340 | 372 | -32 |
| 1973-07-21 | @ HOU | 92 | W 5-3 | 41-51 | 6 | 28,384 | Jerry Koosman | Ken Forsch | Jerry Koosman | Ken Forsch | Harry Parker | 345 | 375 | -30 |
| 1973-07-22 | @ HOU | 93 | W 3-2 | 42-51 | 6 | 27,663 | Tom Seaver | Jerry Reuss | Tom Seaver | Jerry Reuss | | 348 | 377 | -29 |
| 1973-07-26 | @ SLN | 94 | L 1-13 | 42-53 | 6 | 0 | Jon Matlack | Bob Gibson | Bob Gibson | Jon Matlack | | 349 | 390 | -41 |
| 1973-07-26 | @ SLN | 95 | L 1-2 | 42-53 | 6 | 35,557 | Jerry Koosman | Alan Foster | Alan Foster | Jerry Koosman | Diego Segui | 350 | 392 | -42 |
| 1973-07-27 | @ SLN | 96 | W 2-1 | 43-53 | 6 | 26,379 | Tom Seaver | Rick Wise | Tom Seaver | Rick Wise | | 352 | 393 | -41 |
| 1973-07-28 | vs MON | 97 | W 11-3 | 44-53 | 6 | 26,600 | George Stone | Mike Torrez | George Stone | Mike Torrez | | 363 | 396 | -33 |
| 1973-07-29 | vs MON | 98 | L 4-6 | 44-54 | 6 | 28,205 | Ray Sadecki | Craig Caskey | Mike Marshall | Ray Sadecki | | 367 | 402 | -35 |
| 1973-07-30 | vs MON | 99 | L 0-1 | 44-56 | 6 | 0 | Jon Matlack | Steve Rogers | Steve Rogers | Jon Matlack | | 367 | 403 | -36 |
| 1973-07-30 | vs MON | 100 | L 2-5 | 44-56 | 6 | 25,960 | Tug McGraw | Steve Renko | Mike Marshall | Buzz Capra | | 369 | 408 | -39 |
| 1973-07-31 | vs PIT | 101 | L 1-4 | 44-57 | 6 | 24,322 | Jerry Koosman | Dock Ellis | Dock Ellis | Jerry Koosman | Ramon Hernandez | 370 | 412 | -42 |
| 1973-08-01 | vs PIT | 102 | W 3-0 | 46-57 | 6 | 0 | Tom Seaver | Steve Blass | Tom Seaver | Steve Blass | | 373 | 412 | -39 |
| 1973-08-01 | vs PIT | 103 | W 5-2 | 46-57 | 6 | 27,189 | George Stone | Nelson Briles | George Stone | Nelson Briles | Harry Parker | 378 | 414 | -36 |
| 1973-08-02 | vs PIT | 104 | W 5-1 | 47-57 | 6 | 13,429 | Ray Sadecki | Jim Rooker | Ray Sadecki | Jim Rooker | Tug McGraw | 383 | 415 | -32 |
| 1973-08-03 | vs SLN | 105 | W 7-3 | 48-57 | 6 | 25,764 | Jon Matlack | Rich Folkers | Jon Matlack | Rich Folkers | | 390 | 418 | -28 |
| 1973-08-04 | vs SLN | 106 | L 3-4 | 48-58 | 6 | 22,926 | Jerry Koosman | Bob Gibson | Orlando Pena | Jerry Koosman | Diego Segui | 393 | 422 | -29 |
| 1973-08-05 | vs SLN | 107 | L 2-3 | 48-60 | 6 | 0 | Tom Seaver | Alan Foster | Alan Foster | Tom Seaver | Orlando Pena | 395 | 425 | -30 |
| 1973-08-05 | vs SLN | 108 | L 1-4 | 48-60 | 6 | 40,280 | Jim McAndrew | Rick Wise | Rick Wise | Jim McAndrew | | 396 | 429 | -33 |
| 1973-08-06 | vs SLN | 109 | W 10-3 | 49-60 | 6 | 21,845 | George Stone | Reggie Cleveland | Harry Parker | Reggie Cleveland | | 406 | 432 | -26 |
| 1973-08-07 | vs SLN | 110 | W 6-5 | 50-60 | 6 | 10,519 | Ray Sadecki | Tom Murphy | Buzz Capra | Tom Murphy | Tug McGraw | 412 | 437 | -25 |
| 1973-08-08 | @ LAN | 111 | W 1-0 | 51-60 | 6 | 24,219 | Jon Matlack | Andy Messersmith | Jon Matlack | Andy Messersmith | | 413 | 437 | -24 |
| 1973-08-09 | @ LAN | 112 | L 0-1 | 51-61 | 6 | 24,737 | Jerry Koosman | Claude Osteen | Claude Osteen | Jerry Koosman | | 413 | 438 | -25 |
| 1973-08-10 | @ SFN | 113 | W 7-1 | 52-61 | 6 | 8,692 | Tom Seaver | Juan Marichal | Tom Seaver | Juan Marichal | | 420 | 439 | -19 |
| 1973-08-11 | @ SFN | 114 | L 7-8 | 52-62 | 6 | 15,762 | George Stone | Tom Bradley | Randy Moffitt | Tug McGraw | | 427 | 447 | -20 |
| 1973-08-12 | @ SFN | 115 | L 1-4 | 52-63 | 6 | 13,490 | Ray Sadecki | Ron Bryant | Ron Bryant | Ray Sadecki | | 428 | 451 | -23 |
| 1973-08-13 | @ SDN | 116 | L 2-3 | 52-64 | 6 | 2,440 | Jon Matlack | Bill Greif | Mike Caldwell | Jon Matlack | | 430 | 454 | -24 |
| 1973-08-14 | @ SDN | 117 | L 0-9 | 52-65 | 6 | 3,969 | Jerry Koosman | Randy Jones | Randy Jones | Jerry Koosman | | 430 | 463 | -33 |
| 1973-08-15 | @ SDN | 118 | W 7-0 | 53-65 | 6 | 6,531 | Tom Seaver | Steve Arlin | Tom Seaver | Steve Arlin | | 437 | 463 | -26 |
| 1973-08-17 | vs CIN | 119 | L 1-2 | 53-66 | 6 | 36,803 | George Stone | Don Gullett | Pedro Borbon | Harry Parker | | 438 | 465 | -27 |
| 1973-08-18 | vs CIN | 120 | W 12-1 | 54-66 | 6 | 26,365 | Jon Matlack | Fred Norman | Jon Matlack | Fred Norman | | 450 | 466 | -16 |
| 1973-08-19 | vs CIN | 121 | W 2-1 | 55-66 | 6 | 33,598 | Jerry Koosman | Ross Grimsley | Jerry Koosman | Ross Grimsley | | 452 | 467 | -15 |
| 1973-08-20 | vs CIN | 122 | L 3-8 | 55-67 | 6 | 29,384 | Tom Seaver | Jack Billingham | Clay Carroll | Tug McGraw | | 455 | 475 | -20 |
| 1973-08-21 | vs LAN | 123 | W 2-1 | 56-67 | 6 | 26,351 | Ray Sadecki | Don Sutton | Ray Sadecki | Don Sutton | | 457 | 476 | -19 |
| 1973-08-22 | vs LAN | 124 | W 4-3 | 57-67 | 6 | 25,442 | George Stone | Andy Messersmith | Tug McGraw | Jim Brewer | | 461 | 479 | -18 |
| 1973-08-23 | vs LAN | 125 | L 4-5 | 57-68 | 6 | 26,056 | Jon Matlack | Claude Osteen | Claude Osteen | Buzz Capra | | 465 | 484 | -19 |
| 1973-08-24 | vs SFN | 126 | W 1-0 | 58-68 | 6 | 35,361 | Jerry Koosman | Juan Marichal | Jerry Koosman | Juan Marichal | | 466 | 484 | -18 |
| 1973-08-25 | vs SFN | 127 | L 0-1 | 58-69 | 6 | 38,221 | Tom Seaver | Tom Bradley | Tom Bradley | Tom Seaver | | 466 | 485 | -19 |
| 1973-08-26 | vs SFN | 128 | L 4-5 | 58-70 | 6 | 35,210 | Ray Sadecki | Ron Bryant | Ron Bryant | Ray Sadecki | Elias Sosa | 470 | 490 | -20 |
| 1973-08-27 | vs SDN | 129 | W 6-5 | 59-70 | 6 | 14,790 | George Stone | Steve Arlin | George Stone | Steve Arlin | Tug McGraw | 476 | 495 | -19 |
| 1973-08-28 | vs SDN | 130 | W 8-6 | 60-70 | 6 | 16,801 | Jon Matlack | Clay Kirby | Jon Matlack | Clay Kirby | Tug McGraw | 484 | 501 | -17 |
| 1973-08-29 | vs SDN | 131 | W 3-0 | 61-70 | 5 | 18,436 | Jerry Koosman | Rich Troedson | Jerry Koosman | Rich Troedson | Buzz Capra | 487 | 501 | -14 |
| 1973-08-30 | @ SLN | 132 | L 0-1 | 61-71 | 6 | 19,373 | Tom Seaver | Reggie Cleveland | Al Hrabosky | Tom Seaver | | 487 | 502 | -15 |
| 1973-08-31 | @ SLN | 133 | W 6-4 | 62-71 | 5 | 28,594 | Ray Sadecki | Mike Nagy | Tug McGraw | Diego Segui | | 493 | 506 | -13 |
| 1973-09-01 | @ SLN | 134 | W 4-1 | 63-71 | 5 | 29,197 | George Stone | Alan Foster | George Stone | Alan Foster | Harry Parker | 497 | 507 | -10 |
| 1973-09-02 | @ SLN | 135 | L 4-7 | 63-72 | 5 | 20,339 | Jon Matlack | Rick Wise | Eddie Fisher | Buzz Capra | Diego Segui | 501 | 514 | -13 |
| 1973-09-03 | vs PHI | 136 | W 5-0 | 64-73 | 5 | 0 | Jerry Koosman | Steve Carlton | Jerry Koosman | Steve Carlton | | 506 | 514 | -8 |
| 1973-09-03 | vs PHI | 137 | L 3-6 | 64-73 | 5 | 30,748 | Craig Swan | Dick Ruthven | Dick Ruthven | Craig Swan | Mac Scarce | 509 | 520 | -11 |
| 1973-09-04 | vs PHI | 138 | W 7-1 | 65-73 | 5 | 13,674 | Tom Seaver | Jim Lonborg | Tom Seaver | Jim Lonborg | | 516 | 521 | -5 |
| 1973-09-05 | vs PHI | 139 | W 4-0 | 66-73 | 4 | 12,563 | Ray Sadecki | Wayne Twitchell | Ray Sadecki | Wayne Twitchell | Tug McGraw | 520 | 521 | -1 |
| 1973-09-07 | @ MON | 140 | W 1-0 | 68-73 | 4 | 0 | Jon Matlack | Steve Renko | Jon Matlack | Steve Renko | Tug McGraw | 521 | 521 | 0 |
| 1973-09-07 | @ MON | 141 | W 4-2 | 68-73 | 4 | 24,167 | Jerry Koosman | Mike Torrez | Tug McGraw | Mike Marshall | Ray Sadecki | 525 | 523 | 2 |
| 1973-09-08 | @ MON | 142 | L 1-3 | 68-74 | 4 | 17,632 | Tom Seaver | Steve Rogers | Steve Rogers | Tom Seaver | | 526 | 526 | 0 |
| 1973-09-09 | @ MON | 143 | W 3-0 | 69-74 | 4 | 20,743 | George Stone | Balor Moore | George Stone | Balor Moore | Tug McGraw | 529 | 526 | 3 |
| 1973-09-11 | @ PHI | 144 | L 4-6 | 69-75 | 5 | 8,159 | Jerry Koosman | Jim Lonborg | Jim Lonborg | Jerry Koosman | | 533 | 532 | 1 |
| 1973-09-12 | @ PHI | 145 | W 3-2 | 70-75 | 4 | 8,418 | Jon Matlack | Wayne Twitchell | Jon Matlack | Wayne Twitchell | Tug McGraw | 536 | 534 | 2 |
| 1973-09-13 | @ PHI | 146 | W 4-2 | 71-75 | 4 | 8,194 | Tom Seaver | Ken Brett | Tom Seaver | George Culver | Tug McGraw | 540 | 536 | 4 |
| 1973-09-15 | vs CHN | 147 | W 5-1 | 72-76 | 4 | 0 | George Stone | Fergie Jenkins | George Stone | Fergie Jenkins | Tug McGraw | 545 | 537 | 8 |
| 1973-09-15 | vs CHN | 148 | L 0-7 | 72-76 | 4 | 25,553 | Ray Sadecki | Rick Reuschel | Rick Reuschel | Ray Sadecki | | 545 | 544 | 1 |
| 1973-09-16 | vs CHN | 149 | W 4-3 | 73-76 | 4 | 25,681 | Jerry Koosman | Burt Hooton | Tug McGraw | Burt Hooton | | 549 | 547 | 2 |
| 1973-09-17 | @ PIT | 150 | L 3-10 | 73-77 | 4 | 15,000 | Tom Seaver | Bruce Kison | Bruce Kison | Tom Seaver | Chris Zachary | 552 | 557 | -5 |
| 1973-09-18 | @ PIT | 151 | W 6-5 | 74-77 | 4 | 12,336 | Jon Matlack | Bob Moose | Tug McGraw | Ramon Hernandez | Buzz Capra | 558 | 562 | -4 |
| 1973-09-19 | vs PIT | 152 | W 7-3 | 75-77 | 3 | 29,240 | George Stone | Nelson Briles | George Stone | Nelson Briles | Tug McGraw | 565 | 565 | 0 |
| 1973-09-20 | vs PIT | 153 | W 4-3 | 76-77 | 3 | 24,855 | Jerry Koosman | Jim Rooker | Ray Sadecki | Luke Walker | | 569 | 568 | 1 |
| 1973-09-21 | vs PIT | 154 | W 10-2 | 77-77 | 2 | 51,381 | Tom Seaver | Steve Blass | Tom Seaver | Steve Blass | | 579 | 570 | 9 |
| 1973-09-22 | vs SLN | 155 | W 2-0 | 78-77 | 2 | 24,251 | Jon Matlack | Reggie Cleveland | Jon Matlack | Reggie Cleveland | | 581 | 570 | 11 |
| 1973-09-23 | vs SLN | 156 | W 5-2 | 79-77 | 1 | 51,926 | George Stone | Mike Thompson | Harry Parker | Orlando Pena | Tug McGraw | 586 | 572 | 14 |
| 1973-09-25 | vs MON | 157 | W 2-1 | 80-77 | 1 | 43,805 | Jerry Koosman | Steve Rogers | Jerry Koosman | Steve Rogers | Tug McGraw | 588 | 573 | 15 |
| 1973-09-26 | vs MON | 158 | L 5-8 | 80-78 | 1 | 30,953 | Tom Seaver | Balor Moore | Mike Marshall | Harry Parker | | 593 | 581 | 12 |
| 1973-09-30 | @ CHN | 159 | L 0-1 | 81-79 | 1 | 0 | Jon Matlack | Rick Reuschel | Bob Locker | Jon Matlack | | 593 | 582 | 11 |
| 1973-09-30 | @ CHN | 160 | W 9-2 | 81-79 | 1 | 21,432 | Jerry Koosman | Fergie Jenkins | Jerry Koosman | Fergie Jenkins | | 602 | 584 | 18 |
| 1973-10-01 | @ CHN | 161 | W 6-4 | 82-79 | 1 | 1,913 | Tom Seaver | Burt Hooton | Tom Seaver | Burt Hooton | Tug McGraw | 608 | 588 | 20 |