SAN FRANCISCO - Billy Hamilton and Jay Bruce drove in two runs apiece to lead the Cincinnati Reds to a 6-2 win over the San Francisco Giants on Friday night.

Johnny Cueto (8-5) pitched a three-hitter over 8 1-3 innings and the Reds won their third straight and sixth of seven overall.

Cueto walked two and struck out three, allowing both runs and raising his majors-leading ERA from 1.86 to 1.88.

Aroldis Chapman got the final two outs for his 16th save in 17 chances.

The NL West-leading Giants lost for the 13th time in 17 games. Their once commanding 9 1/2 game lead has dwindled to two after losing for the 10th time in 12 home games.

Pinch hitter Tyler Colvin tripled to drive in the Giants' first run in the sixth and later scored on Pence's groundout.

Cueto faced the minimum over the first four innings. Pablo Sandoval reached on second baseman Brandon Phillip's first error in 70 games and was erased on a double play in the second.

Madison Bumgarner (9-5) gave up a season-high five runs on nine hits, matching his season high. He walked one and struck out three.

Bumgarner needed just 53 pitches to get through four scoreless innings and then threw 26 in the fifth, allowing all five of his runs as the Reds sent 10 men to the plate.

Devin Mesoraco led off with a double, Brayan Pena grounded out to Bumgarner, holding Mesoraco at second. Chris Heisey singled and Zack Cozart singled to score a run. Cueto followed with a bunt, fielded cleanly by catcher Buster Posey. He threw late to third, loading the bases and opening the floodgates.

Hamilton, who had three hits, drove in two with a single, Todd Frazier, who had three hits, singled home a run and after Phillips hit into a fielder's choice, Bruce singled in another run.

Bruce added an RBI single in the seventh against Yusmeiro Petit.

NOTES: Frazier extended his hitting streak against the Giants to 14 games. . The Reds scored first for the 14th time in their last 16 games. . The Reds released OF Roger Bernadina, who refused an assignment to Triple-A Louisville after being designated for assignment. . RHP Alfredo Simon (10-3, 2.92) starts for the Reds on Saturday night. He's 7-1 in nine starts on the road. . RHP Matt Cain (1-6, 4.82) is scheduled to start for the Giants on Saturday night. He's 2-3 in five outings against the Reds at home. . Bumgarner became the first Giants' pitcher to record two pickoffs in the same inning since Bud Black did it in May of 1992. . Giants 1B Brandon Belt was hit by a pitch and hit a home run in his second rehab game in San Jose.