SAN FRANCISCO -- After committing the error that he believed cost his team a regulation win, Cincinnati Reds third baseman Todd Frazier had one thing on his mind when he led off the 10th inning Tuesday.

Make up for it with one swing.

And that he did.

Frazier hit Sergio Romo's third pitch for a solo home run, allowing the Reds to overcome a late rally by the San Francisco Giants for a 9-8 victory.

"In times of adversity," Frazier said, "you have to pick yourself up."

The homer was the 34th of the season for the All-Star Game Home Run Derby champ. It came immediately after the Giants scored twice in the ninth against Reds closer Aroldis Chapman, the game-tying run being unearned thanks to Frazier's throwing error on Matt Duffy's infield single.

"Crazy last inning," Frazier said. "I threw the ball away. Maybe I should have eaten it, but I had him with a good throw.

"I just thought, 'You've got to pick yourself up. Put a little fire in yourself.' I got a good pitch to hit."

The win was Cincinnati's fourth in the past six games against National League playoff hopefuls, and the Reds evened the three-game series at one win apiece.

"I just like the way we've been playing, the effort we're putting in on a daily basis," Reds manager Bryan Price said. "We're getting contributions from different guys."

The Giants saw their four-game winning streak end in a roller-coaster affair in which they trailed 3-0, led 5-3 and trailed 8-5 before forcing a 10th inning.

"They were fighting, trying to find a way to win it," Giants manager Bruce Bochy said. "Tough loss. We had our chances. Just couldn't finish it."

The Giants forced extra innings by scoring a total of three times against Chapman in the eighth and ninth innings, tying the score on catcher Buster Posey's one-out single in the ninth that scored Duffy.

Chapman (4-4), who was shooting for his 31st save, instead wound up with the win. Right-hander Jumbo Diaz pitched around a two-out double by left fielder Alejandro De Aza in the last of the 10th for his first career save.

Romo (0-5) had allowed just one run in his previous 23 outings.

San Francisco appeared destined for a regulation loss after Reds pinch hitter Ramon Cabrera capped a wild five-run, seventh-inning rally with a two-run single, giving Cincinnati an 8-5 lead.

Overcoming two outs at home plate and a rare triple review that went against them, the Reds turned a two-run deficit into a three-run lead with the benefit of two Giants errors, two walks and a hit batsman.

The Reds had a run taken away on video review, when the New York crew ruled that reserve outfielder Skip Schumaker was out at the plate after initially being called safe.

The lengthy review also confirmed two other questionable calls on the play -- that the batter, center fielder Jason Bourgeois, properly ran in his lane en route to first base, and that there was no fan interference when Giants right fielder Marlon Byrd tracked down an errant throw near the Reds bullpen.

Price was sure afterward that the video team got the call wrong, insisting there was fan interference, which would have sent Schumaker safely back to third base.

"We were able to win anyway," he said, not wanting to get himself in trouble with the league office.

The key pinch hit by Cabrera, who had four hits in Monday's 5-3 loss to the Giants, came off right-hander George Kontos, making it a five-run inning.

The Giants' two-pronged rally against Chapman included a pinch-hitting appearance by pitcher Madison Bumgarner, who drew a two-out walk with two on in the eighth.

"It's tough no matter who you face in the major leagues," Bumgarner said of hitting against Chapman. "Just got to lay off balls and swing at strikes. Keep it as simple as I can."

Neither starting pitcher -- Reds left-hander John Lamb and Giants righty Chris Heston -- factored in the decision.

Shortstop Ivan De Jesus Jr., who had a two-run triple in a three-run first off Heston, drove in three runs for the Reds. Phillips had three hits and two RBIs.

Posey and pinch hitter Jarrett Parker hit homers for the Giants, who lost for just the ninth time in their past 34 home games. Posey finished with four RBIs.

Duffy had three hits, and first baseman Brandon Belt added two doubles for the Giants, who out-hit the Reds 13-9.

Heston survived a three-run Reds first inning during which the Giants had right-hander Yusmeiro Petit warming up in the bullpen. De Jesus' two-out, two-run triple capped the inning and gave Cincinnati a 3-0 lead.

Heston allowed only one more hit, and no more runs, before leaving for pinch hitter Parker in the fifth. All told, he surrendered three runs on three hits, walked four and struck out eight in five innings.

Posey's homer, his 18th, got the Giants even in the third, setting the stage for Parker's go-ahead homer two innings later.

Parker's blast came on the first pitch thrown by Reds reliever Ryan Mattheus.

Lamb was pulled after four innings, having allowed three runs on six hits. He struck out three and did not walk a batter.

NOTES: The Reds won for the 10th time in their past 13 games at AT&T Park. ... The Giants scored at least five runs for the sixth time in eight games. ... San Francisco recorded a season-high-tying three errors. ... PH Madison Bumgarner became just the second pitcher ever to bat against Reds LHP Aroldis Chapman and the first to reach base. ... LHP John Lamb's start Tuesday was the 45th straight by a Reds rookie. The last Cincinnati game not started by a rookie was pitched by RHP Mike Leake, who is currently employed by the Giants.