Peavy will look to lead San Francisco to its first home sweep of Arizona in more than three years.The Giants (80-65) have limited the Diamondbacks to a run and six hits while taking the first two games. Ryan Vogelsong threw 6 2/3 innings in Wednesday's 5-0 victory and three relievers combined for a perfect 2 1/3 to preserve the two-hitter.It marked a season-best eighth straight home win, a streak in which Angel Pagan is batting .441. The Giants haven't won nine straight at AT&T Park since May 6-22, 2011. Their last home sweep of Arizona also came during that streak from May 10-12."The pitching's been doing the job and (we're getting) defense and timely hitting," said Gregor Blanco, who was 2 for 4 and has hit .362 over his last 18 games. "That's awesome and it's fun to watch."San Francisco has won 11 of 14 overall and is 2 1/2 games behind NL West-leading Los Angeles.Peavy (4-4, 2.36 ERA) is 4-1 with a 1.04 ERA in his last five starts. He was an 8-2 winner at Detroit on Friday, yielding two unearned runs in six innings. He successfully lobbied manager Bruce Bochy to pitch the final three innings after a 2 hour, 42 minute rain delay."Tonight was a big one. Every game's big. We know that," said Peavy, who was honored by the Giants before Wednesday's game for surpassing the 2,000 career strikeout mark against Milwaukee on Aug. 30.One of the biggest keys to Peavy's turnaround since joining the Giants has been his ability to limit home runs. He's given up just two over 53 1/3 innings with San Francisco after previously surrendering a career-worst 1.45 per nine innings in his 20 starts for Boston.Arizona doesn't appear to be much of a threat to disturb that trend with just one home run in its past nine games and only 108 on the season to rank 13th in the NL.Better run support has helped Peavy's cause, too. The right-hander received 38 runs of support over 124 innings with the Red Sox, but has received 34 runs of support in 70 2/3 fewer innings with the Giants.He's 14-12 with a 4.57 ERA in 30 career outings versus Arizona, winning three straight. He last saw them in a 5-2 victory for Boston on Aug. 3, 2013, allowing two runs over seven-plus innings.Miguel Montero is the only current Diamondback hitting better than .167 in at least four at-bats against Peavy, going 6 for 20 with a home run and two doubles.The Diamondbacks (59-86) are looking to avoid a sixth straight loss, which would match skids from Aug. 16-21 and April 11-16 as their worst of the season.Ender Inciarte and Mark Trumbo are a combined 4 for 35 during the losing streak, which has seen Arizona produce only six runs.Randall Delgado (3-3, 5.40) comes off a strong showing, holding San Diego to two hits over five scoreless innings in a 5-1 road victory last Thursday as Arizona's switch to a six-man rotation prompted his first start since April 10.Delgado had been 2-5 with a 6.04 ERA in his previous 13 starts dating back to last season, including a 6-5 loss at San Francisco on April 10 when he yielded three runs in 3 1/3 innings. However, he's 1-1 with a 2.00 ERA in seven career games -- four starts -against the Giants.