SAN FRANCISCO -- Leadoff hitters do not often bat with the bases loaded, which is unfortunate for the Atlanta Braves, who have one of the best in baseball in Jace Peterson.

On Sunday, the young second baseman improved to 5-for-8 with 14 RBIs with the bases loaded in his career when he capped a four-run, ninth-inning rally with a bases-clearing triple, lifting the Braves to a 7-5 victory over the San Francisco Giants.

"I don't know. I just like people on base," assured Peterson, who has 21 RBIs this season. "That's when you dig down a little."

In winning their second in a row to earn a split in the four-game series, the Braves overcame a 5-3 deficit in the ninth against Giants closer Santiago Casilla with the help of an error on shortstop Brandon Crawford on what could have been the final play of the game.

After Casilla began the ninth by getting Braves third baseman Juan Uribe to ground out, first baseman Freddie Freeman got Atlanta within one with a solo home run, his seventh of the season. Freeman had entered the game as a defensive replacement two innings earlier on a day that began with him pleading Braves manager Fredi Gonzalez to let him start.

"I guess it was the right decision," Freeman noted after his late-game appearance allowed his streak of 218 consecutive games played to continue.

Shortstop Andrelton Simmons then followed with a walk, but Casilla then got catcher Christian Bethancourt to hit what appeared to be a game-ending, double-play grounder. However, Crawford booted the routine play, keeping the Braves alive with just one out.

Pinch-hitter A.J. Pierzynski then blooped a single to right to load the bases before Peterson lined a triple to left-center to score three runs and put the Braves on top 7-5.

"I was just looking for something over the plate," Peterson said. "I put a good swing on it, and it worked out well for us."

Peterson, who had a career-best three hits in Atlanta's 8-0 win Saturday, added two more hits Sunday. The Braves improved to 11-6 when he has batted leadoff.

"You can say a lot about our team. One thing we're not short of is the fight," Gonzalez gushed. "We split a four-game set against a real good club. I'm very proud of the guys."

Right-hander Jason Grilli, the fourth Atlanta pitcher, retired three of the four Giants he faced in the ninth for his 15th save.

Right-hander Nick Masset (1-1) got the win after pitching 1 2/3 innings of scoreless relief. Casilla (4-1) took the loss when blowing a save for the third time in 18 chances.

Giants manager Bruce Bochy had a left-hander, Javier Lopez, warming up in the bullpen before the left-handed-hitting Peterson's game-winning hit, but elected to stick with the right-hander Casilla.

"I like to show confidence in him," Bochy said of Casilla, whose 15 saves are tied with Grilli for the second-most in the National League. "I've got my closer in there. If they catch the ground ball ... there's nothing he (Casilla) can do."

First baseman Brandon Belt, Crawford and second baseman Joe Panik all homered for the Giants, who finished May with a National League-best 21-9 record.

"Great month," Bochy assured. "Would have been nice to get this one. That's baseball. You have to deal with games like this occasionally. Hopefully not often."

Panik's homer, a two-run shot in a three-run seventh inning, gave the Giants a two-run lead after the Braves went ahead 3-2 in the top of the inning on Uribe's two-run homer off Giants starter Madison Bumgarner.

Going for his fifth win in the month of May, Bumgarner held the Braves to one run on two hits before walking left fielder Jonny Gomes with one out in the seventh. Uribe, a former Giants player, followed with his second homer in two days, the 28th of his career at AT&T Park, to give Atlanta a brief 3-2 lead.

Bumgarner was charged