Wacha (10-7) gave up one run, four hits and two walks as he bounced back from a tough stretch. In his three previous starts he was 0-3 with a 10.22 ERA.
The Cardinals moved within 5 1/2 games of the idle Colorado Rockies in the NL wild card race. They failed to gain ground in the NL Central as the first-place Chicago Cubs defeated the Atlanta Braves to maintain a six-game lead.
Tommy Pham was 3 for 4 with a double and two RBIs for St. Louis.