|- style="background:#bfb" | 21 || May 3 || Astros || 3–2 || Kent Tekulve (2–0) || Frank DiPino (1–3) || None || 17,330 || 9–12 |- style="background:#bfb" | 22 || May 4 || Astros || 7–5 (13) || Dave Rucker (1–0) || Bill Dawley (0–2) || None || 25,521 || 10–12 |- style="background:#fbb" | 23 || May 5 || Astros || 3–4 || Joe Niekro (2–3) || Shane Rawley (3–2) || Frank DiPino (4) || 27,506 || 10–13 |- style="background:#fbb" | 24 || May 7 || Reds || 0–2 || Mario Soto (5–2) || Kevin Gross (2–3) || Ted Power (4) || 21,902 || 10–14 |- style="background:#fbb" | 25 || May 8 || Reds || 2–8 || Jay Tibbs (2–4) || John Denny (1–3) || None || 22,416 || 10–15 |- style="background:#fbb" | 26 || May 10 || @ Mets || 0–5 || Dwight Gooden (5–1) || Steve Carlton (0–3) || None || 46,143 || 10–16 |- style="background:#fbb" | 27 || May 11 || @ Mets || 0–4 || Sid Fernandez (1–0) || Shane Rawley (3–3) || Roger McDowell (1) || 29,635 || 10–17 |- style="background:#fbb" | 28 || May 12 || @ Mets || 2–3 || Ron Darling (3–1) || Kevin Gross (2–4) || Jesse Orosco (4) || 32,597 || 10–18 |- style="background:#fbb" | 29 || May 13 || @ Reds || 3–7 || John Stuper (4–2) || John Denny (1–4) || None || 12,068 || 10–19 |- style="background:#bfb" | 30 || May 14 || @ Reds || 7–1 || Charles Hudson (1–2) || Tom Browning (3–2) || None || 10,079 || 11–19 |- style="background:#fbb" | 31 || May 15 || @ Braves || 2–3 (10) || Bruce Sutter (2–0) || Kent Tekulve (2–1) || None || 10,292 || 11–20 |- style="background:#fbb" | 32 || May 16 || @ Braves || 3–6 || Jeff Dedmon (1–0) || Larry Andersen (0–2) || Bruce Sutter (6) || 10,116 || 11–21 |- style="background:#bfb" | 33 || May 17 || Dodgers || 10–5 || Kevin Gross (3–4) || Jerry Reuss (2–4) || None || 16,334 || 12–21 |- style="background:#bfb" | 34 || May 18 || Dodgers || 7–5 || Larry Andersen (1–2) || Tom Niedenfuer (1–2) || Don Carman (1) || 24,189 || 13–21 |- style="background:#fbb" | 35 || May 19 || Dodgers || 2–3 || Fernando Valenzuela (4–4) || Charles Hudson (1–3) || Ken Howell (5) || 35,276 || 13–22 |- style="background:#bfb"