Cincinnati, OH (SportsNetwork.com) - Brandon Belt finished 3-for-5 with a three-run homer and three runs scored, while Buster Posey added a two-run blast as San Francisco ripped Cincinnati by a 10-2 count in the second edition of a four-game series.
Casey McGehee, Angel Pagan, Brandon Crawford and Justin Maxwell each knocked in a run for the Giants, who snapped a two-game losing streak -- including a 4-3 defeat in Thursday's opener -- thanks to exploding for a season high in runs scored.
Madison Bumgarner (4-2) worked seven innings and gave up two runs on eight hits with four strikeouts.
"Ten runs is pretty nice when you're out there pitching," said Bumgarner. "We're playing good right now. I like the way everyone is going about their business."
Zack Cosart and Billy Hamilton went deep for the Reds, whose three-game win streak came to an end.
Jason Marquis (3-3) was out after only three innings, after allowing six runs on seven hits.
Belt got things started on his first-inning blast, which came after Gregor Blanco walked and Joe Panik singled.
"It was a challenge to get back into that ballgame against Bumgarner," said Reds manager Bryan Price. "He had good stuff, as expected. It just wasn't our best ballgame."
Cozart got a run back in the home half on his one-out shot to left, but Panik started the third with a base hit and scored two batters later on Posey's homer which made it 5-1. Belt singled, Maxwell walked and McGehee plated Belt with a two-out hit for a five-run bulge.
Hamilton's two-out solo homer in the bottom of the fifth cut the hosts' deficit to four, then back-to-back RBI doubles by Belt and Maxwell followed by a run-scoring hit from Crawford boosted the Giants' edge to 9-2 in the seventh.
Pagan's eighth-inning groundout put San Francisco into double digits and Yusmeiro Petit held Cincinnati off the board in its final two turns at the plate.
The defending World Series champs' previous high for runs in one contest was eight, set at Houston on Tuesday ... Cincinnati allowed 10-or-more runs one previous time this season, in a 16-10 win at Milwaukee on April 21 ... Prior to the contest, Giants manager Bruce Bochy revealed that right fielder Hunter Pence would be activated from the disabled list on Saturday. Pence has not played this season after suffering a broken left arm early in spring training.