Trouble brewed immediately.
The Braves opened the game with two perfectly-placed hits, as Wainwright struggled to get his body and arm in sync during his delivery. That issue, which affects Wainwright's release point, then continued through a 20-pitch span in which he walked three consecutive hitters.
The first two, drawn by Freddie Freeman and Dan Uggla, were issued after Wainwright got ahead 0-2. At some point in each at-bat, he had a borderline pitch called a ball. Wainwright then walked Brian McCann, also with the count full.
"That's a matter of putting guys away when you're ahead," Wainwright said. "I tried to make them nasty [pitches] rather than just throwing them and trusting they'd be good."
Two of the walks came with the bases loaded. Wainwright had only done that once in 908 previous innings.
"You need to pick up pretty quick on what [the home plate umpire is] going to call [a strike]," St. Louis manager Mike Matheny said. "You can't wait until late in the count like that to get a real nasty pitch on the edge or just a bit off called [a strike]."
Wainwright, who had already reviewed tape of the inning before issuing his postgame comments, did not criticize home-plate umpire Wally Bell. He did add, though, that he was "a couple pitches away from being a quality outing."
After a visit from pitching coach Derek Lilliquist, Wainwright made the adjustment he needed to with his body and recorded three straight outs to strand the bases full. But he needed 39 pitches to get through the frame. His pitch count was 75 by the end of the third, and the Braves used three straight hits in that inning to plate another run.
"He was making good pitches," said Atlanta second baseman Dan Uggla. "We were just fighting and having good at-bats. We just battled and tried to get his pitch count up."
Wainwright loaded the bases again in the fifth, but was given the chance to try to work out of trouble by his manager, who knew his bullpen needed rest. The move didn't pay off.
RBI hits by shortstop Tyler Pastornicky and opposing starter Brandon Beachy staked Atlanta to a five-run lead.
"You have bases loaded three times," Wainwright said, "you're asking for trouble."
Beachy was the final batter of the night for Wainwright, who threw a season-high 108 pitches. He saw his two-game winning streak snapped and was unable to finish five innings for just the second time this year.
The loss was also Wainwright's first in seven career starts against the organization that drafted him. He entered the night 6-0 with a 2.24 ERA against Atlanta.
"One thing that was positive is that he competed, he never stopped competing," Braves manager Fredi Gonzalez said. "That's his strength."
Wainwright's early dismissal extended a recent trend among the team's starters. They have pitched past the fifth only three times in the last eight games. The pitching staff as a whole has a 4.68 ERA in May after a 2.61 in April.
Credit should go to Fernando Salas, though, for saving the bullpen. Having spent the last week focused on righting a mechanical issue, Salas followed Wainwright with 2 2/3 scoreless innings.
"Now I'm feeling much better," Salas saidy. "My fastball is down. I feel good. My changeup works much better now, and my slider is down. My fastball command has been much better. Today we didn't win, but everything worked [for me]."
It didn't for J.C. Romero. The lefty allowed five runs while not recording an out in his last appearance. He gave up another two on four hits in two innings Saturday.
"It seems like, for the most part, every strike that I throw that has a little more of the plate than I would like, it seems like it's being hit," Romero said. "Sometimes it's about strikes. Sometimes it's about throwing quality strikes."
Beachy handled his early lead with ease. He didn't allow a hit until the fourth and allowed just one runner into scoring position through five. The Cardinals' only run off the right-hander came on Allen Craig's sixth-inning sacrifice fly. Any chance of adding on in that inning ended when David Freese, with two on, grounded into a double play.
"[Beachy] was putting a little bit of movement on the ball, but hitting his spots," Matheny said. "The big curveball was really a difference maker, too. He was able to take considerable speed off it and kept everybody off balance."
St. Louis scored again in the eighth when Daniel Descalso tripled and scored on Rafael Furcal's second single of the night. Furcal is riding an 11-game hitting streak, matching Jon Jay for the longest by a Cardinal this season.
By dropping the first two games, the Cards' string of winning home series comes to an end. They had won each of their previous four home series this year.