SAN FRANCISCO -- The late Earl Weaver didn't invent the three-run home run.

He just popularized it.

It was fitting, then, that on what would have been the Hall of Famer's 86th birthday Sunday, the three-run homer was back in vogue in Baltimore Orioles' baseball.

Jonathan Schoop completed a six-run comeback by belting a three-run homer with two outs in the ninth inning, allowing the Orioles to overtake the San Francisco Giants 8-7 and earn a series win in the interleague matchup.

Matt Wieters had a career-high five hits and Mark Trumbo smacked his major-league-leading 34th home run as the Orioles rallied from a 7-1 deficit with two runs in the seventh inning and two in the eighth before Schoop's blast.

"Earl Weaver's birthday. Three-run homer," Orioles manager Buck Showalter said with a chuckle. "Wish I'd thought of that."

The Orioles' 34th come-from-behind win wasn't secured until record-setting closer Zach Britton pitched out of a two-on, two-out jam in the bottom of the ninth for his 37th consecutive save this season and 41st dating to last September.

Britton got Denard Span to ground into a fielder's choice on a full-count pitch with runners at first and second to end the game.

"It was fun to watch," said Britton, who did nothing but spectate until after the Orioles had taken the lead. "But you have to stay focused."

The win allowed the Orioles to complete a 5-5 trip, just the second time this season they've won at least half their games on a trek.

"The road can beat you up. Especially where we've been," Showalter noted. "Happy flight (home). It's nice to get a day off (Monday)."

With the victory, Baltimore (66-51) was able to stay within a half-game of first-place Toronto (67-51) in the American League East.

The Orioles trailed 7-5 entering the ninth before Manny Machado lined a one-out single and took second when the ball got by left fielder Angel Pagan for an error.

Giants closer Santiago Casilla (2-4) struck out Chris Davis for the second out, but then walked Trumbo, setting the stage for Schoop's 18th homer of the season.

The blown save was Casilla's sixth of the season.

"I threw the curve ball; I just made a mistake," he admitted. "The ball didn't break."

Right-hander Brad Brach (7-1), the fourth Orioles pitcher, got the win after pitching a 1-2-3 eighth inning.

Wieters contributed to both the seventh- and eighth-inning uprisings, doubling in the seventh and singling in the eighth. He added a triple in the ninth following Schoop's homer.

Trumbo's homer, a solo shot, came in the eighth.

"Our whole mindset is: Give the offense a chance," Britton said of a bullpen that shut out the Giants on six hits over the final 4 2/3 innings. "The hardest thing is to stay engaged, especially when you're that far behind. Credit to our offense for getting us back in it."

Backup catcher Trevor Brown, a last-minute replacement for ailing Buster Posey, drove in three runs with three hits to help the Giants build their lead.

Posey was a late scratch from manager Bruce Bochy's initial starting lineup because of lower-back soreness.

Brown opened the game's scoring with an RBI single in the second inning and highlighted a four-run fifth with a two-run single, helping San Francisco open a 7-1 lead.

Hunter Pence's eighth homer of the season, his first blast since May 18, also contributed to the Giants' advantage.

But in the end, it wasn't enough.

"They have a dangerous lineup (Nos.) 1-8 there. They can hurt you," Bochy said of the Orioles. "That's what happened today."

San Francisco starter Johnny Cueto, who helped his own cause with two hits and an RBI, took the 7-1 lead into the seventh. But he was pulled after Hyun Soo Kim's two-out RBI double, his third hit, that got the Orioles back within 7-3.

Seeking a 14th win and first since the All-Star break, Cueto allowed three runs on eight hits in his 6 2/3 innings. He walked one and struck out four.

"Like we say. There isn't an easy out in their lineup. It's one of the best I faced all year," Cueto said of the Orioles. "There's no reason for us to walk with our heads down.

Orioles starter Wade Miley was tagged for seven runs (six earned) in 4 1/3 innings. He gave up eight hits and one walk, striking out one.

Pagan had a pair of doubles and Eduardo Nunez and Brandon Crawford scored twice apiece for the Giants, who have won just one series since the All-Star break.

Jones drove in two runs and Machado had two hits for the Orioles.

NOTES: The ninth-inning, go-ahead home run was the second of Schoop's career. He also had one last season (July 10) against Washington. ... Orioles RF Mark Trumbo matched his career-best with his 34th home run. ... The Giants hadn't blown a six-run lead at home since Sept. 10, 2013 against Colorado. ... Orioles manager Buck Showalter recorded his 1,405th career win, tying Jimmy Dykes for 27th place on the all-time list. ... Bochy (1,768) remained one win behind Jim Leyland (1,769) in their battle for 15th place. ... Bochy managed his 3,501st game Sunday.