Jhonny Peralta added a two-run homer for the Cardinals (66-37), who have won eight of 11 to move a season-high 29 games over .500 for the third time this season. Stephen Piscotty had a two-run double to help St. Louis run its major league-best home record to 39-15.
The six-hitter for Wacha (12-4) and two relievers came after St. Louis bolstered its bullpen by acquiring Jonathan Broxton before the non-waiver trade deadline on Friday afternoon. The Cardinals sent minor league outfielder Malik Collymore to Milwaukee for Broxton, who will help set up for All-Star closer Trevor Rosenthal.
Colorado has lost seven of 10.
Carpenter, who hit two homers and drove in four runs in a 9-8 win over Colorado on Thursday, also had a double and reached three times.
Wacha gave up four hits, struck out seven and walked one - his only free pass came to Carlos Gonzalez in the sixth, the result of an 11-pitch battle. Wacha did not allow more than one baserunner in any inning.
Carpenter slammed a first-inning leadoff home run off right-hander Kyle Kendrick (4-12), who left after one inning with shoulder inflammation. It was Carpenter's seventh career leadoff homer and third this season.
Kendrick has surrendered a major league-high 26 home runs.
Wacha, who had given up 10 runs over 11 innings in his previous two starts, retired seven in a row at one point.
The Cardinals broke the game open with five runs in the sixth. Peralta hit his 15th homer off Christian Friedrich.
Rockies: OF Corey Dickerson was not in the lineup after suffering a right rib contusion in the fifth inning of Thursday's loss. Dickerson, who had two stints on the DL earlier this season with plantar fasciitis, is listed as day to day.
Cardinals: Matt Holliday is on the 15-day DL after he strained his right quad on Wednesday. It is the same muscle strain that forced him to miss 31 games earlier in the season. ''To kind of take a step back like this is frustrating,'' Holliday said.
St. Louis RHP Lance Lynn (8-5, 2.71 ERA) will face LHP Jorge De La Rosa (6-4, 5.03 ERA) on Saturday. Lynn is 2-0 with a 1.37 ERA in four career starts against Colorado. De La Rosa has a 3-3 career mark in St. Louis.
Link to box score: St. Louis (66-37) 7, Colorado (43-58) 0