ATLANTA -- Tommy Pham was disappointed when he didn't make the St. Louis roster out of spring training. After being recalled on Friday, the outfielder is trying to make it difficult for the Cardinals to send him down again.
"I didn't look at it any different," said Pham, who was recalled from Triple-A Memphis on Friday when Stephen Piscotty went on the disabled list with a right hamstring strain. "I knew I was going to be in the lineup, I've played up here before so there's no nervousness. I took it like any other challenge, make sure I'm prepared and ready to go.
Pham's go-ahead homer came against Josh Collmenter (0-1) and scored Magneuris Sierra, who had reached on second baseman Jace Peterson's error. Pham, who also hit a solo homer in the third, now has three long balls this season. He finished the game with three RBIs, two runs and a stolen base.
After seeing the Braves leave the potential winning run on base in the 11th, 12th and 13th inning, Pham wanted to get the game over with when given a chance.
"I was pumped," Pham said. "I was telling everybody in the dugout, 'Let's go.' I was joking around, 'We don't get paid for overtime.' When Peterson made that error, it was our chance, and coincidentally I was the guy up with the opportunity. To come through and get the over with was huge."
Manager Mike Matheny said, "Just the kind of guy we get accustomed to seeing around here. He comes in here and does some huge things for us. Love to watch these guys get their opportunities and make the most of it."
The winning pitcher was Sam Tuivailala (1-0), who pitched two scoreless innings. Kevin Siegrist tossed a scoreless 14th for his first save.
St. Louis improved to 2-2 in extra-inning games and won its sixth straight on the road. Atlanta dropped to 1-3 in extra innings. It is the second year in a row the Cardinals have swept a series in Atlanta.
The Braves have lost four in a row and six of their past seven.
St. Louis starter Michael Wacha threw six innings and allowed two runs on five hits and two walks with six strikeouts. He left with a 4-2 lead.
After Matt Bowman and Brett Cecil each gave up a run to allow the Braves to tie the game, the Cardinals got single scoreless innings of relief from Trevor Rosenthal, Jonathan Broxton and Seung Hwan Oh.
Atlanta starter R.A. Dickey allowed four runs on eight hits and two walks over six innings, but he allowed two homers. He has given up eight homers in six starts.
"It wasn't my best effort, but it wasn't my worst either," Dickey said.
"They gave us a chance," Atlanta manager Brian Snitker said. "They gave us an opportunity to stretch the game."
The Cardinals took a 1-0 lead on Matt Carpenter's solo home run, his seventh. It was the third straight game in which Carpenter homered.
St. Louis added three runs in the third on a solo homer by Pham and RBI doubles from Randal Grichuk and Jedd Gyorko.
Atlanta cut lead to 4-3 with an unearned run in the seventh off Bowman. Peterson hit into a double play, but a video replay showed he beat the throw to first base. Given second life, Peterson stole second and advanced to third when Yadier Molina's throw went into center field. Dansby Swanson then broke an 0-for-7 streak with an RBI single.
The Braves tied the game in the eighth on a solo homer by Freeman, his 11th, off southpaw Cecil.
Atlanta had chances to win the game in extra innings but repeatedly left the winning run on third base. Kemp struck out to end the threat in the 10th, Ender Inciarte grounded out to end the 11th, and Kurt Suzuki struck out to end the 12th.
NOTES: St. Louis 2B Kolten Wong extended his hitting streak to 12 games with a double in the third inning. He went 1-for-7. ... The Cardinals placed OF Jose Martinez on the 10-day disabled list with a left groin strain and recalled OF Magneuris Sierra from Class A Palm Beach. Sierra got his first major league hit in the sixth off Braves RHP R.A. Dickey but was promptly picked off. ... Atlanta will have Monday off and begin a two-game series in Houston. RHP Bartolo Colon (1-3, 6.47 ERA) will oppose Houston RHP Charlie Morton (3-2, 3.97), a former Brave, in the opener. ... St. Louis continues its six-game road trip with a three-game stop in Miami. St Louis will send RHP Carlos Martinez (1-3, 3.75) against Miami LHP Adam Conley (2-2, 6.12) in the opener on Monday.