double-header |- style="background:#fbb" | 21 || May 10 || Padres || 3–5 || Clay Kirby (3–1) || Woodie Fryman (1–1) || None || 7,601 || 13–8 |- style="background:#bfb" | 22 || May 11 || Padres || 6–5 (12) || Wayne Twitchell (2–0) || Gary Ross (0–1) || None || 9,224 || 14–8 |- style="background:#fbb" | 23 || May 12 || Dodgers || 1–6 || Don Sutton (5–0) || Dick Selma (1–3) || None || 24,205 || 14–9 |- style="background:#fbb" | 24 || May 13 || Dodgers || 1–3 || Claude Osteen (4–1) || Steve Carlton (5–2) || Jim Brewer (3) || 27,003 || 14–10 |- style="background:#bbb" | – || May 14 || Dodgers || colspan=6 | Postponed (rain); Makeup: July 10 as a traditional double-header |- style="background:#bfb" | 25 || May 15 || Cubs || 4–0 || Woodie Fryman (2–1) || Ferguson Jenkins (3–3) || None || 8,133 || 15–10 |- style="background:#fbb" | 26 || May 16 || Cubs || 1–8 || Burt Hooton (3–3) || Bill Champion (3–1) || None || 12,326 || 15–11 |- style="background:#fbb" | 27 || May 17 || Cubs || 2–3 || Tom Phoebus (1–1) || Steve Carlton (5–3) || Dan McGinn (4) || 12,528 || 15–12 |- style="background:#fbb" | 28 || May 19 || Mets || 3–8 || Buzz Capra (3–1) || Dick Selma (1–4) || Danny Frisella (3) || 20,451 || 15–13 |- style="background:#fbb" | 29 || May 20 (1) || Mets || 1–3 || Jon Matlack (5–0) || Woodie Fryman (2–2) || None || see 2nd game || 15–14 |- style="background:#fbb" | 30 || May 20 (2) || Mets || 1–2 || Jerry Koosman (1–3) || Bill Champion (3–2) || Tug McGraw (7) || 36,691 || 15–15 |- style="background:#fbb" | 31 || May 21 || Mets || 3–4 || Tom Seaver (7–1) || Steve Carlton (5–4) || Danny Frisella (4) || 57,267 || 15–16 |- style="background:#fbb" | 32 || May 22 || @ Expos || 3–6 || Mike Torrez (4–1) || Barry Lersch (1–2) || None || 17,676 || 15–17 |- style="background:#fbb" | 33 || May 23 || @ Expos || 2–6 || Bill Stoneman (4–4) || Dick Selma (1–5) || None || 12,757 || 15–18 |- style="background:#fbb" | 34 || May 24 || @ Expos || 1–4 || Carl Morton (2–4) || Woodie Fryman (2–3) || None || 9,341 || 15–19 |- style="background:#fbb" | 35 || May 26 || @ Pirates