PHOENIX -- Johnny Estrada's big offensive day will force him to take some extra rest.
Estrada doubled home the tying run in the second inning, then later in the inning came home with what proved to be the decisive run.
"I got some good pitches to hit and was able to get the bat on some," Estrada said.
However, he tweaked a quad injury that he's been battling since fouling a pitch off his leg against San Diego about two weeks ago. Estrada, who raised his average to .321, will sit out the series finale Sunday in favor of Chris Snyder and then get a second day off with Arizona idle on Monday.
"He's got that upper quad and every time he hits a ball in the gap it seems to be barking on him," Arizona manager Bob Melvin said. "It seems like just when it gets better, he hits another ball in the gap."
Estrada's hitting made a winner of Claudio Vargas, who rebounded from first-inning struggles to record his second consecutive home win.
Vargas (4-1) allowed an inside-the-park home run to Felipe Lopez in the first and walked the bases full. But he struck out Brandon Phillips to cap the 42-pitch inning trailing only 1-0.
"After that I controlled the ball like I'm supposed to," Vargas said. "I said, 'Here's my best stuff. Hit it."'
Beginning with Phillips, Vargas retired 16 of the final 19 batters he faced. He allowed one run on four hits with three walks and six strikeouts.
"In the first inning we really had a chance to do something," Cincinnati manager Jerry Narron said. "We were one hit away from doing some damage early."
Jose Valverde, the fourth Arizona pitcher, pitched the ninth for his ninth save in 10 tries.
Arizona remained in a first place tie with Colorado in the NL West.
Bronson Arroyo (5-1) allowed two runs in the second and another in the fourth in his first loss of the season. The Reds retained their half-game lead in the NL Central with Houston's 5-0 loss at Colorado.
Conor Jackson led off the second with a double to left and scored on Estrada's first double, a line drive into the right-field corner, to tie the game 1-1. Estrada later scored on a two-out RBI single by Craig Counsell for a 2-1 lead.
The Diamondbacks made it 3-1 in the fourth when Estrada doubled, went to third on a single by Orlando Hudson and scored on a Craig Counsell groundout to second.
Arroyo allowed three runs on a career-worst 11 hits with one walk and one strikeout.
"Sometimes you pitch better that your line shows," Arroyo said. "This was one of those nights that I pitched worse than my line looked. I felt like I had decent stuff but those guys had a great approach against me. They were on my stuff better than anyone has been this year."
Lopez's home run came when his line drive hit a padded column in left-center field and bounced away from center fielder Jeff DaVanon.
The Reds have been held to one run in each of their last two games.
"We've got a good hitting ball club," Narron said. "We're going to start scoring some runs. We just haven't put it together in the last week or so."
Estrada became the 10th Arizona player to hit three doubles in a game and the second this season. Chad Tracy also hit three doubles on April 22 at Los Angeles. ... Lopez's inside-the-park homer was the Reds' first since Ken Griffey Jr.'s game-ending homer August 20, 2001, at Cinergy Field off St. Louis' Alan Benes. It was the third inside-the-park homer in Chase Field's nine-year history. ... DaVanon singled in the first to snap an 0-for-17 skid.