St. Louis (87-69) has won three straight games and six of seven. The Cardinals began the day 1½ games ahead of Colorado, which played later Sunday, and remained two games behind Milwaukee, the wild card leader. St. Louis hosts the Brewers (89-67) in a three-game series starting Monday night.
Mikolas (17-4) allowed two runs — one earned — and two hits in seven innings with eight strikeouts and no walks. John Brebbia and Giovanny Gallegos finished a five-hitter.
Andrew Suarez (7-12) gave up two runs and six hits in five innings. The Giants finished 31-50 on the road for a two-year record of 57-105 away from home.
San Francisco has lost 10 straight road games against NL Central teams since winning at the Chicago Cubs on May 27.
The bottom two in the Cardinals batting order built a 2-0 lead with two-out singles, by Yairo Munoz in the second and Mikolas in the fourth.
Harrison Bader bunted in a run to spark a five-run sixth that includes RBI singles by Munoz and Paul DeJong around Jose Martinez's two-run double. Carpenter hit a two-run homer off Casey Kelly in the eighth
Brandon Crawford's two-run homer in the seventh stopped an 0-for-9 skid.
TRAINING ROOM
Cardinals: 2B Kolten Wong missed his second consecutive start after leaving Friday's game in the seventh inning with cramps in both hamstrings.
DEBUT
INF Edmundo Sosa was recalled from Triple-A Memphis. Sosa made his debut when he walked as a pinch-hitter in the eighth, and he scored on Carpenter's home run.
UP NEXT
Giants: LHP Derek Holland (7-8, 3.57 ERA) starts the first of a three-game series at home against San Diego and RHP Bryan Mitchell (1-4, 6.16 ERA) on Monday night. Holland will make his first start since July 18, which was also against the Padres, where he allowed four runs in five innings.
Cardinals: RHP Jack Flaherty (8-8, 3.08 ERA) kicks off a three-game home series Monday night against Milwaukee and RHP Chase Anderson (9-8, 3.93 ERA). Flaherty is 1-1 with a 2.35 ERA in four career starts against the Brewers.
