ATLANTA -- Marcus Giles got a chance to extend his hitting streak.
He would have been fine with the game ending three innings earlier.
Andruw Jones added to his major league lead with two more homers, sending the Braves to the ninth with a 4-1 lead. But the Giants rallied for three runs off John Smoltz.
That gave Giles two extra at-bats in extra innings. He struck out in the 10th but came through in the 12th with two runners on, lining a single to left off Brian Cooper (0-1).
"I was thinking, 'Geez, you're not to make out again, are you?'" Giles quipped. "I was just trying to put a ball in play up the middle. I missed one hanging slider by swinging too hard. I stepped out and told myself to relax. A single was as good as a homer."
Wilson Betemit, who led off the inning with a walk after striking out four straight times, easily beat the throw home.
"It was nice to keep the hitting streak alive," Giles said. "But I would have been happy going 0-for-3 and getting a 4-1 win."
Blaine Boyer (1-1) earned his first major league win with two scoreless innings.
The Giants' comeback ruined a strong outing by Smoltz, who had a two-hit shutout through seven. Even though he gave up a run in the eighth, manager Bobby Cox was persuaded to let his right-hander go out for the ninth with a three-run lead.
It was the wrong move.
"That's the way I am," Smoltz said. "The easy thing to do is protect yourself and not go out there, but that's never been me."
Smoltz gave up three line-drive hits, including Ray Durham's RBI single that made it 4-3, before Cox went to the bullpen. Chris Reitsma gave up two more hits, sandwiched around J.T. Snow's run-scoring groundout that brought home the tying run, also charged to Smoltz.
Jones' two-run homer in the sixth was his 36th of the season, equaling his career highs from 2000 and '03. He didn't wait long to set a new personal best, leading off the eighth with his 37th.
It was Jones' seventh multihomer game of the season. He came into the night with two more homers than anyone else in the big leagues.
"It's just home runs," Jones said with a shrug. "I don't worry about what the numbers are going to be at the end of the season."
Atlanta rookie Jeff Francoeur had an RBI single, extending his hitting streak to 11 games.
Smoltz was roughed up in his last start, allowing five runs over six innings in an 11-3 loss at St. Louis that ended his eight-game winning streak.
Mindful of Smoltz's elbow problems over the years, Cox gave his top starter the chance to take a couple of extra days between starts. But Smoltz decided to take his regular turn.
Through seven, he dominated the struggling Giants.
"The game was over," Smoltz said. "I was about as in control as I've ever been in a long time. To have it slip away like that certainly is disappointing. But to come back and get the win is gratifying."
San Francisco starter Kevin Correia (1-4) struck out a career-high seven through the first four innings, fanning the side in both the first and third innings.
The Braves got to Correia in the fifth. Adam LaRoche led off with a double off the wall and came home when Francoeur doubled over the outstretched glove of right fielder Michael Turner.
Atlanta made it 3-0 in the sixth on Jones' 407-foot drive into the right-center seats on a 1-0 pitch from Correia.
"It started off well," Correia said. "I wish I had ended better."
The Giants ruined Smoltz's shutout in the eighth. It started with Edgardo Alfonzo's liner to left that skidded off the glove of Kelly Johnson and was generously ruled a double. Mike Matheny took advantage of the defensive lapse with an RBI single.
Jones restored the three-run lead with his homer off LaTroy Hawkins in the bottom half, but Smoltz and Reitsma couldn't hold it.
"I'd really be upset had we not won this game," Smoltz said.
Both teams used pitchers as pinch-hitters in the 12th. Noah Lowry lined out for San Francisco, and Atlanta's Horacio Ramirez popped out on a bunt attempt. ... Cooper was called up from the minors last weekend to start in place of the ailing Brett Tomko. ... The Giants dropped to 1-54 when trailing after eight innings.