@ Pirates || 3–2 || Art Mahaffey (5–0) || Vern Law (19–6) || None || 18,487 || 49–80 |- style="background:#fbb" | 130 || September 4 || @ Pirates || 3–5 || Vinegar Bend Mizell (10–7) || Jim Owens (3–12) || Clem Labine (6) || 17,856 || 49–81 |- style="background:#fbb" | 131 || September 5 || Reds || 2–9 || Bob Purkey (16–8) || Robin Roberts (9–14) || None || 8,979 || 49–82 |- style="background:#fbb" | 132 || September 6 || Reds || 1–6 (10) || Jim Brosnan (7–2) || John Buzhardt (4–14) || None || 4,396 || 49–83 |- style="background:#bfb" | 133 || September 7 || Cubs || 2–0 || Gene Conley (8–12) || Don Cardwell (7–13) || None || 3,323 || 50–83 |- style="background:#fbb" | 134 || September 8 || Cubs || 1–2 || Glen Hobbie (14–17) || Art Mahaffey (5–1) || None || 3,808 || 50–84 |- style="background:#fbb" | 135 || September 9 || Cardinals || 1–5 (5) || Larry Jackson (16–12) || Robin Roberts (9–15) || None || 18,677 || 50–85 |- style="background:#bfb" | 136 || September 10 || Cardinals || 7–2 || Jim Owens (4–12) || Ray Sadecki (8–8) || None || 6,444 || 51–85 |- style="background:#fbb" | 137 || September 11 || Cardinals || 3–7 || Curt Simmons (7–3) || John Buzhardt (4–15) || Lindy McDaniel (24) || 3,722 || 51–86 |- style="background:#bbb" | – || September 12 || Dodgers || colspan=6 | Postponed (rain; Hurricane Donna); Makeup: September 13 as a traditional double-header |- style="background:#fbb" | 138 || September 13 (1) || Dodgers || 1–2 (10) || Johnny Podres (12–11) || Gene Conley (8–13) || Larry Sherry (7) || see 2nd game || 51–87 |- style="background:#fbb" | 139 || September 13 (2) || Dodgers || 1–4 || Sandy Koufax (8–12) || Art Mahaffey (5–2) || None || 7,559 || 51–88 |- style="background:#bfb" | 140 || September 14 || Giants || 5–1 || Robin Roberts (10–15) || Billy O'Dell (7–12) || None || 4,432 || 52–88 |- style="background:#fbb" | 141 || September 15 || Giants || 6–8 (11) || Johnny Antonelli (6–7) || Turk Farrell (9–6) || Billy Loes (5) || 4,847 || 52–89 |- style="background:#fbb" | 142 || September 16 || @ Braves || 0–4 || Warren Spahn (20–9) || John Buzhardt (4–16) || None || 6,117 || 52–90 |- style="background:#bfb" | 143 || September 17 || @ Braves || 5–2 (10) || Turk