The win carried heightened importance as a bounce back from Sunday's deflating 18-inning loss to the D-backs in the longest Major League game of the season.
Peavy (6-6) allowed seven hits, three runs (two earned) and walked two in a performance that Padres manager Bud Black called very "Jake-like."
Peavy certainly wasn't "Jake-like" in his last start -- in which a viral bug limited Peavy to one inning in a 10-5 loss to the Phillies last Tuesday.
Much talk circulated during the past week about both of his health issues -- the aggravated ankle and general fatigue from illness.
"Even when he was warming up before the game, he was feeling a little pain," Padres catcher Henry Blanco said. "We thought he was going to be a little weak from the flu, but he was good tonight. He was aggressive."
Peavy allowed two runs in the fourth inning when Chris Snyder and Gerardo Parra scored to give the D-backs a 2-0 advantage.
With the Padres trailing, 2-0, in the fifth inning, Peavy advanced runners Blanco and Josh Wilson on a sacrifice bunt. Tony Gwynn then singled to score Blanco and advance Wilson to third. The Padres tied the score at 2 when second baseman David Eckstein hit a sacrifice fly to score Wilson.
Third baseman Kevin Kouzmanoff, who tied his career high with four RBIs, hit a two-run single in the fifth inning to give the Padres a 4-2 lead. He also extended the Padres' lead to 6-3 in the seventh inning with a two-run double.
Gwynn went 2-for-3 with two runs, an RBI and walk in his fifth multihit game of the season.
"We talked about a lineup situation where all guys have to contribute, and tonight it happened," Black said.
The collaborative contribution was much needed considering that Padres first baseman Adrian Gonzalez had three walks. Gonzalez, who leads the Major Leagues in home runs with 22, has now had at least two walks in seven consecutive games.
"We've talked about the need for these guys behind him and these guys in front of him to get on so it will be much more difficult for these guys to try to pitch around him," Black said.
Peavy threw 105 pitches, 70 for strikes, in the win. He now has 92 career victories, which ties him for second on the Padres' all-time list.
"I'm OK. It's just a little tender when you're on for seven innings," Peavy said of his ankle. "It's one of those things that you just get through."
Black described Peavy's ankle as a "gradual healing" situation that does not affect his delivery. Peavy originally injured his ankle running the bases against the Cubs on May 22.
"The lateral movement is what gets him," Black said. "The straightforward, off-the-mound pitching, I think, is fine."
Peavy said he "would be lying" if he claimed to be 100 percent, but he did classify the pain as "manageable."
"We feel like I'm not doing anything to put my arm or myself in jeopardy," Peavy said. "I want to be out there for these guys. I want to battle and get in that Wild Card race and hopefully make a run at the Dodgers."