"We should have him up with runners in scoring position and two outs more," Arizona manager Bob Melvin said.

The Diamondbacks have won three straight for the first time since August 19-21 against the Pirates and trimmed the Dodgers' division lead to 3 1/2 games. Los Angeles lost 15-8 at Pittsburgh.

"This was the first opportunity we've had in a while where we look up, they lost and we could capitalize on it," Melvin said. "It's nice to finally pick up a game. Three and a half is better than four and a half."

Justin Upton and David Eckstein went deep for Arizona, which has 11 games left.

"Our goal is to win our ballgames and not worry about what they do," Upton said.

The Diamondbacks led 7-3 after eight innings but nearly blew it in the ninth. Doug Slaten walked Scott McClain and Eugenio Velez to start the inning and Tony Pena surrendered a two-run triple to Omar Vizquel.

Rich Aurilia's run-scoring groundout cut it to 7-6 but Pena retired Dave Roberts and Randy Winn on consecutive grounders to second for his third save in seven chances.

"When Vizquel got the big hit we had good hitters coming up," manager Bruce Bochy said. "We'd done a good job of coming back but we came up a little short."

Webb (21-7) allowed three runs - two earned - and eight hits. But his bat was more effective than his sinker early on.

Arizona scored five runs in the second inning to erase a 3-1 deficit. Chris Snyder started the rally with a one-out walk and advanced to second on Chris Young's single off Jonathan Sanchez (9-11).

Eckstein flied out but Webb followed with a tying two-run double to the center-field wall. The right-hander's hit snapped the Diamondbacks' 0-for-25 skid with runners in scoring position.

"It ended up being a pretty big hit, looking back on it," Webb said. "I just got a pitch I could hit and squared it up."

Webb scored on Stephen Drew's single and Upton added his 14th homer, a towering shot onto the concourse above the center-field fence.

"Everyone gets hot," Upton said. "It's all about us winning ballgames and trying to do whatever I can do."

Webb avoided serious trouble from there, allowing only one more runner to reach second and holding San Francisco scoreless over his final six innings.

"They're a team that swings early and likes to be aggressive which helped me with the pitch count" said Webb, who threw 57 of his 88 pitches for strikes.

Sanchez allowed six runs and six hits in 3 2-3 innings. He walked three, struck out four and was disappointed he couldn't help teammate Tim Lincecum in the race for the NL Cy Young Award.

"Everyone says Webb will win it but Timmy has better numbers and Timmy's started to win," Sanchez said. "I wanted to beat him. I wanted to beat Webb to make it easier for Timmy."

Pablo Sandoval went 2-for-4 and drove in a run for San Francisco. Bengie Molina had an RBI single in the first.

Drew went 4-for-5 and scored two runs for Arizona.

Notes

Webb is 4-0 against San Francisco this season. ... Upton has three homers in his last five games. The last two landed within a few feet of each other on the center-field concourse. ... Winn is 16-for-27 against Webb in his career. ... Sanchez has lasted less than four innings three times this season.