Yadier Molina gave St Louis a 1-0 lead in the second inning with his eighth homer. The Braves answered with two runs in the bottom of the inning.
Wainwright allowed four runs, three earned, on seven hits and one walk in seven innings.
MARLINS 2, PIRATES 0
In Miami, Henderson Alvarez earned his first National League victory, while Giancarlo Stanton hit his 12th homer as the Miami Marlins managed another low-scoring victory, beating the Pittsburgh Pirates 2-0 on Friday night.
The Marlins are 4-4 since the All-Star break, even though they have totaled only 15 runs.
Jeff Locke (9-3) allowed only two earned runs in 6-2/3 innings and had a career-high nine strikeouts, but he lost for the first time in his past 10 road starts. His ERA rose to 2.15.
In other NL action, it was:
‧ Mets 11, Nationals 0, Game 1
‧ Nationals 2, Mets 1, Game 2
‧ Rockies 8, Brewers 3
‧ Diamondbacks 10, Padres 0
‧ Dodgers 2, Reds 1
‧ Cubs 3, Giants 2
In interleague play, it was:
‧ Tigers 2, Phillies 1