Sam Tuivailala allowed three singles in two-thirds of an inning to give the Giants their fourth run of the night.
Brett Cecil came in for Tuivailala to end the inning and the threat by getting a soft comebacker. Heading to the bottom of the frame, the Cardinals lead 5-4.
Fowler puts Cardinals back on top with three-run homer
The Cardinals took advantage of a much-maligned Giants bullpen in the bottom of the seventh.
Second baseman Kolten Wong was first in line, as he led off the inning with a walk. Pinch hitter Jhonny Peralta, in his first at-bat since being activated from the 10-day disabled list, then singled up the middle to push Wong to third.