Behind the strength of an Adrian Gonzalez two-run, first-inning homer, and a three-run sixth inning, the Padres staked Peavy to a 5-0 lead as the ballclub took two of the three games in the series.
Gonzalez, who didn't start on Tuesday because of a touch of the flu, added an RBI single in that three-run sixth as the Padres won for the 11th time in their last 12 games. Gonzalez's home run, his Major League-leading 18th of the seaason, came off D-backs starter and loser Billy Buckner (1-1) a batter after David Eckstein singled.
Gonzalez said there was no doubt he was ready to play on Wednesday.
"I was playing. I felt a lot better," said Gonzalez, whose missed start on Tuesday night was his first since April 17, 2008. "I was actually able to sleep. I didn't cough all night. I just felt a lot better throughout the day. I'm just trying to get rid of a little congestion, but strength-wise, I'm OK."
Peavy won his 91st game for the Padres, moving him one behind Randy Jones, who holds second place in team annals with 92 victories. The late Eric Show is the all-time franchise leader with 100 wins.
Peavy's three straight victories came after losing his previous four decisions. He worked into the seventh, but he was unable to hold the five-run lead his offense gave him going into the bottom of the sixth, when the D-backs scored three times. Peavy came out after allowing one-out singles to Ryan Roberts and Augie Ojeda in the seventh, and the D-backs eventually pulled to 5-4.
The Padres added three runs in the eighth on an infield hit, four walks and an RBI single, putting the game out of reach.
Peavy was touched for eight hits and four runs in his 6 1/3 innings. He walked one and struck out five. Not his typical numbers. In the Cubs game, for instance, he pitched six innings, allowed no runs, two hits, walked four and whiffed 10, the 30th time in his career he reached double digits in strikeouts in a single game.
San Diego manager Bud Black termed Peavy's injury in medical terms as a posterior tibialis strain, a common running injury of the tendon near the rear inside of the ankle. Black also said that it seemed to wear on Peavy as the game grew longer.
"Earlier in the game, I don't think it bothered him," Black said. "But later it might have hampered his ability to stay on top of the ball. You guys might have also noted the way he was running. He was taking it pretty easy."
As proof, Peavy's fastball tailed off to 90-91 mph in his latter innings, and the D-back hitters were just sitting on it. He allowed two hits and no runs during the first five innings, but was pelted for four runs on six hits in the final nine batters he faced.
"I just got stiff and lost some adrenalin," Peavy said. "I didn't make good pitches. Even earlier in the game, I tried to change speeds a little bit and get quick outs. But I didn't make any pitches to start the sixth inning. I don't know what to tell you. I really felt about the same all night. It's just one of those things."
In any event, it was all good for the Padres, who came into the series on an 11-game road losing streak, dating back to an April 28 victory over the Rockies in Colorado, which is their next stop on this six-game trip, beginning on Friday night.
The road series victory was only the Padres' third of the season and first since they took two of three at Philadelphia in a rain-shortened series from April 17-19. Earlier during the same trip, the Padres took two-of-three from the Mets from April 13-16 in the inaugural series at Citi Field.