Twitchell (3–4) || None || 6,456 || 13–14 |- style="background:#bbb" | – || May 12 || Reds || colspan=6 | Postponed (rain); Makeup: May 15 as a traditional double-header |- style="background:#bfb" | 28 || May 13 || Reds || 4–0 || Tom Underwood (4–3) || Gary Nolan (1–3) || None || 11,634 || 14–14 |- style="background:#bfb" | 29 || May 14 || Reds || 4–0 || Steve Carlton (2–4) || Pat Darcy (1–2) || None || 30,908 || 15–14 |- style="background:#bfb" | 30 || May 15 (1) || Reds || 6–3 || Tug McGraw (2–0) || Don Gullett (4–2) || None || see 2nd game || 16–14 |- style="background:#bfb" | 31 || May 15 (2) || Reds || 5–3 || Gene Garber (2–2) || Clay Carroll (3–4) || Tug McGraw (3) || 24,038 || 17–14 |- style="background:#bfb" | 32 || May 16 || Braves || 12–8 || Gene Garber (3–2) || Buzz Capra (3–5) || None || 18,710 || 18–14 |- style="background:#bfb" | 33 || May 17 || Braves || 9–8 || Gene Garber (4–2) || Phil Niekro (3–4) || None || 30,369 || 19–14 |- style="background:#bfb" | 34 || May 18 || Braves || 5–1 || Tom Underwood (5–3) || Ron Reed (4–4) || None || 25,905 || 20–14 |- style="background:#fbb" | 35 || May 19 || @ Astros || 2–4 || Tom Griffin (2–5) || Steve Carlton (2–5) || Wayne Granger (4) || 7,049 || 20–15 |- style="background:#fbb" | 36 || May 20 || @ Astros || 2–4 || Ken Forsch (2–2) || Tug McGraw (2–1) || Joe Niekro (2) || 7,211 || 20–16 |- style="background:#fbb" | 37 || May 21 || @ Astros || 0–4 || Larry Dierker (5–4) || Wayne Twitchell (3–5) || None || 8,135 || 20–17 |- style="background:#fbb" | 38 || May 23 || @ Reds || 2–5 || Gary Nolan (3–3) || Larry Christenson (0–1) || Clay Carroll (3) || 36,197 || 20–18 |- style="background:#fbb" | 39 || May 24 || @ Reds || 2–3 (11) || Clay Carroll (4–4) || Tug McGraw (2–2) || None || 36,165 || 20–19 |- style="background:#fbb" | 40 || May 25 || @ Reds || 3–4 || Clay Kirby (3–3) || Jim Lonborg (3–2) || Rawly Eastwick (1) || 25,726 || 20–20 |- style="background:#bfb" | 41 || May 26 || Giants || 1–0 (11) || Tug McGraw (3–2) || Ed Halicki (1–1) || None || 15,693 ||