PHOENIX -- Phil Gosselin and Patrick Corbin are developing into a nice one-two punch for the Arizona Diamondbacks.

Since Gosselin was activated Aug. 31, he hit a three-run home run in both games Corbin started. Gosselin's second-inning shot Monday gave Corbin more support than he needed in the Diamondbacks' 6-1 victory over the San Francisco Giants at Chase Field.

"He said he wanted me to pitch every day, because both times he's had three-run homers," Corbin said.

Gosselin has two homers in 23 at-bats for Arizona, which acquired him from the Atlanta Braves in June for pitchers Bronson Arroyo and Touki Toussaint. He spent 3 1/2 months on the disabled list with a fractured thumb before homering in his second game with Arizona on Sept. 2, helping Corbin to a 6-3 victory in Colorado.

"When you miss that much time at the major league level, you never know what it is going to be like when you come back," Gosselin said. "I feel healthy. I feel good, but you never really know.

"Especially with a new team, you want to do well and show these guys that you can play, but at the same time, you don't want to put too much pressure on yourself. Just trying to go out there and play and let the results be what they may."

Gosselin's homer made it 3-0 in the second inning, and center fielder A.J. Pollock hit a bases-empty homer the sixth for a 6-0 lead, both off Giants right-hander Mike Leake.

Corbin (5-3) fired six shutout innings, giving up six hits and no walks while striking out five. The left-hander lowered his ERA to a season-best 3.32 in his 12th start of the year. He has thrown 62 1/3 innings after missing the 2014 season following Tommy John surgery.

"It feels like I've thrown 200 innings already this year," Corbin said. "Just being out for 16 months, now around 60 innings, I'm just trying to maintain and make sure everything in my arm feels good."

Corbin also drove in a run with a bases-loaded single in a two-run fourth inning as the Diamondbacks (66-72) broke a four-game losing streak.

"Just trying to keep the inning going," Corbin said. "It's a plus any time I get on base.

First baseman Buster Posey had three hits and center fielder Angel Pagan and right fielder Marlon Byrd had two for the Giants (71-67). San Francisco lost for the eighth time in 10 games to fall eight games behind the NL West-leading Los Angeles, pending the result of the Dodgers' game against the Angels later Monday. The Giants are nine games out of the second NL wild card.

Posey singled home the Giants' run in the eighth inning after Joe Panik's pinch-hit double, his first plate appearance after missing 35 games with back inflammation. The Giants left runners on first and second in the first inning and first and third with no outs in the fourth.

"We just couldn't do anything offensively," San Francisco manager Bruce Bochy said. "We had our chances, but we got to get some guys come through and deliver."

Gosselin, Pollock, left fielder David Peralta, third baseman Jake Lamb and shortstop Nick Ahmed had two hits apiece for Arizona.

Pollock, who also had a sacrifice fly in the fourth inning, has 45 hits and 17 RBIs in his past 31 games, improving his batting average to .317.

Leake (9-8) gave up six runs and 11 hits, tying his season high, in 5 2/3 innings. The Giants had nine runs and 11 hits against him in an 11-2 victory May 16, when he was with the Cincinnati Reds.

"It was a hanging slider that he put a charge into," Leake said of Gosselin's homer. "He was a tough at-bat the whole day."

NOTES: RHP Brett Bochy had his contract purchased from Triple-A Sacramento when San Francisco RHP Tim Lincecum was transferred from the 15-day to the 60-day disabled list. Bochy, son of Giants manager Bruce Bochy, was 6-1 with a 2.95 ERA in 43 appearances with Sacramento. ... Arizona will recall RHP Jhoulys Chacin and LHP Andrew Chafin from Triple-A Reno on Tuesday, after Reno's season ends, manager Chip Hale said. Chacin is likely to get at least one more start for the Diamondbacks, Hale said. ... Giants LHP Jeremy Affeldt (shoulder strain) is expected to be activated from the disabled list Tuesday, Bruce Bochy said.