ATLANTA -- Gift Ngoepe is best known for his late-inning defense, not his bat. He may have altered that perception on Wednesday night when he helped the Pittsburgh Pirates pull out an improbable win.

Ngoepe, who entered the game hitting only .200, slashed an opposite-field double to drive in the go-ahead run in the 10th inning and begin a seven-run outburst that carried the Pirates to an 12-5 victory over the Atlanta Braves at Sun Trust Park.

"Gift came up with a big at-bat," Pittsburgh's Josh Harrison said. "You could kind of feel it in the dugout when he got that big knock to give us the lead. It took a little bit of pressure off the rest of the squad."

The Pirates came from two runs down with two outs in the ninth to tie the score on Jose Osuna's two-run single -- a rally started by Ngoepe's infield single -- and force extra innings.

"Considering where we've been to this point of the season, it's nice to know that guys are still going up there battling," Harrison said. "We're not quitting until that last out. ... You give us a little breathing room and we're going to try to take advantage of it and that's what we did."

Pittsburgh unloaded in the 10th against Josh Collmenter (0-2), the only available reliever in the Atlanta bullpen, for seven hits -- three of them on consecutive home runs from David Freese, Osuna and Jordy Mercer.

"You can't figure it out. You can't draw it up," Pittsburgh manager Clint Hurdle said. "It was fun to watch."

The winning pitcher was Felipe Rivero (2-1), who pitched a scoreless ninth inning.

Osuna and Adam Frazier led the 14-hit attack with two hits and three RBIs apiece. Frazier also walked four times.

The Pirates trailed 5-3 going into the ninth inning and rallied to tie the score against Jose Ramirez, who was trying to nail down his first career save. Jim Johnson and Arodys Vizcaino, the team's two relievers with closing experience, were unavailable.

Ngoepe and Frazier led off with back-to-back singles. Harrison then launched a fly to deep right center that Ender Inciarte chased down and caught with a leap against the fence.

Ramirez struck out Bell and walked Freese to load the bases before Osuna tied the score with a two-run single to left.

"(Ramirez) was the fresh one down there and he'd been doing a great job," Atlanta manager Brian Snitker said. "That ninth inning is a little different animal and until you've experienced it and it was good opportunity for him to experience that."

Ramirez said, "It is a little different, to be honest. I was just trying to execute the pitches, but they weren't going my way. All I can focus on is the next time I go out there to try to execute and go my way and work out better."

The Braves took the lead with a four-run outburst in the sixth. Brandon Phillips, Nick Markakis and Matt Kemp started the rally with three straight hits off starter Trevor Williams, with Phillips scoring.

The Pirates brought in reliever Juan Nicasio, who retired the first two batters he faced but allowed an RBI single to rookie Rio Ruiz and a double to Peterson. The run ended a streak of 13 consecutive scoreless appearances for Nicasio.

The Braves added a run in the eighth against Johnny Barbato on a double by Ruiz and a ground-rule double by pinch-hitter Danny Santana, who ended an 0-for-18 streak.

Atlanta starter Julio Teheran had his best home start of the season. He pitched six innings and allowed three unearned runs, four hits and two walks, striking out six.

"After the home run, he settled in and was really good and put himself in chance to win the game," Snitker said. "Thought it was really good, actually."

Pittsburgh scored first on Frazier's three-run homer in the second inning, his second homer of the season.

Mercer led off with a single. With one out, Danny Ortiz rolled a potential double-play grounder to shortstop, but it was booted by Jace Peterson. After Williams sacrificed them into scoring position, Frazier hit a rope into the right-field stands.

NOTES: The last time the Pirates scored seven runs in an extra inning was when they produced eight against the Cincinnati Reds on May 25, 2007. It was the first time Atlanta allowed seven runs in an extra inning since allowing the Reds did it on June 13, 1985. ... The Pirates last hit three consecutive home runs in 2013 against the Chicago Cubs. ... CF Andrew McCutchen was not in the starting lineup but delivered a pinch-hit single and scored in the 10th inning. Danny Ortiz started in center field. ... Atlanta manager Brian Snitker sat SS Dansby Swanson. Jace Peterson, normally a second baseman, got his third start at shortstop. Swanson entered the game in the eighth inning for defense. ... Pittsburgh SS Jordy Mercer has hit safely in 18 of 20 career games against Atlanta. ... Thursday's game begins at 12:10 p.m. ET. Atlanta is 4-9 in day games and the Pirates are 10-7 this season.