Tommy Pham finished with two doubles, a single and two RBIs and Yadier Molina added a two-run double as the third-place Cardinals (79-72) gained a game on Colorado in the wild-card race to move within 2 ½ games. St. Louis sits five games behind the Cubs in the NL Central chase.
Rookie right-hander Luke Weaver retired 10 straight batters in one stretch on the way to his seventh straight winning start, the major leagues' longest active streak and the longest by a Cardinals pitcher this season. The 24-year-old allowed five hits and two runs with seven strikeouts in five innings.
Weaver (7-1) has fanned seven or more batters in each of his last seven starts. Relievers Zach Duke, Seung Hwan Oh, Sandy Alcantara and Sam Tuivailala teamed up to retire 12 of the final 13 Reds batters.
Carpenter led off the game with his 21st homer. Fowler followed Pham's RBI double in the third with a two-run shot into the right field seats. It was his career-high 18th homer of the season. DeJong added his team-high 24th, the Cardinals' second set of back-to-back homers in two nights.
The Reds broke up Weaver's shutout bid with a two-run fifth. Patrick Kivlehan's drove in Jose Peraza from first with a double and scored on Jesse Winker's single.
Rookie Davis (1-3) gave up all three homers and five runs on five hits with three strikeouts in three innings.
