SAN FRANCISCO -- Brandon Webb's victory total now equals the career-best 16 victories he had during his Cy Young Award season of a year ago.
While he doesn't feel nearly as sharp, the results are still there.
"That's our goal all year, to take two out of three," Reynolds said. "It's going to flip back and forth a few times, but we're getting down to the nitty gritty now and have to start winning some games."
When Reynolds and Snyder connected in the second, it marked the second time this season the D-backs hit back-to-back home runs. Chad Tracy and Reynolds did so July 3 at St. Louis.
The first-place Diamondbacks increased their lead to 3½ games over the Padres in the NL West, after San Diego lost 6-1 at Los Angeles. The Giants were all but eliminated from playoff contention.
"Every win now is huge," Webb said. "When you take a series, that's what you're trying to do. ... Statistics-wise, this feels similar to last year. It doesn't feel quite as good. I don't know why."
Webb (16-10) retired the first nine Giants batters before Dave Roberts tripled leading off the fourth and scored moments later on a single by Nate Schierholtz, who got the Giants within 3-2 when he came home on Ray Durham's RBI groundout.
Webb allowed four runs and seven hits in seven innings, struck out two and didn't have a walk for the first time in seven starts and for only the third time this year.
"The guy gets better every year, which is kind of scary to think about," Arizona manager Bob Melvin said.
Stephen Drew drove in two runs with a ground-rule double in the ninth that appeared to be a home run had a fan not interfered.
Nevertheless, Arizona generated more than enough offense for Webb to take the series a day after the D-Backs saw their six-game winning streak snapped with a 2-1 defeat.
"He's tough," Giants skipper Bruce Bochy said. "He was throwing strike one, getting the groundballs. That's why he won the Cy Young Award last year. We got ourselves in a bad situation and the ball had eyes."
The Diamondbacks lead the season series 8-7 -- six of those victories by one run -- with three more next week in the desert. Arizona has lost the past five season series with its division rival.
Barry Bonds had the night off and is still at 762 home runs after what could have been his next-to-last homestand with the Giants. He is a free agent after the season.
The 43-year-old slugger will probably play two out of three games this weekend at San Diego, then two more during a three-game set at Arizona early next week.
"Barry's been playing a lot," manager Bruce Bochy said. "Just watching, I think he needs a day."
Giants starter Jonathan Sanchez (1-4) lasted only three-plus innings and threw 80 pitches before leaving with the bases loaded in the fourth. After plunking Snyder at the start of the inning, he gave up back-to-back singles to Drew and Augie Ojeda before Scott Atchison relieved.
Webb grounded into a fielder's choice (Snyder was foced out at home), then Byrnes hit a sacrifice fly to center.
Sanchez is winless in his past six starts dating to last season, going 0-3 since beating the Reds on Sept. 6, 2006, at Cincinnati.
The rookie left-hander is 0-2 in four career outings against Arizona.
"I just threw too many pitches," Sanchez said. "That's why I didn't get more innings. I gave up two home runs and said, 'I've got to get back into the game.' I didn't have command today."
- LHP Erick Threets made his major league debut in the ninth for the Giants.
- Schierholtz, a rookie making quite a push for a 2008 roster spot, stole his second base after his fourth-inning single.
- The Giants activated RHP Randy Messenger from the 15-day disabled list after he had surgery on his broken left hand.
- The last time San Francisco allowed back-to-back home runs was Aug. 11, two off Tim Lincecum by the Pittsburgh Pirates.
- Arizona 3B Tracy took live batting practice ahead of schedule, a day after hitting soft-toss swings in the indoor cage part of his recovery from tendinitis in his right knee. He has been on the DL since Aug. 15.
- Olympic gold medalist beach volleyball player and Stanford graduate Kerri Walsh attended the game.