Jesus Guzman's two-run homer kick-started a six-run eighth inning the San Diego Padres used to down the Arizona Diamondbacks, 7-1, in the opener of a three-game series at Petco Park.
Cameron Maybin added two hits, including an RBI triple, while Alexi Amarista scored twice for the Padres, who snapped a six-game losing streak.
Andrew Cashner (3-3) tossed a scoreless inning of relief to earn the win. Clayton Richard started the game for San Diego and allowed one run on seven hits and a walk over 6 2/3 innings.
Wade Miley (6-2) gave up four runs on six hits with no walks through 7 1/3 innings to take the loss.
Paul Goldschmidt and Willie Bloomquist each had a pair of hits for Arizona, which lost for the third time in four games.
Arizona was able to break a scoreless tie in the third inning when Aaron Hill reached first on a fielder's choice and rounded the bases on a pair of singles by Justin Upton and Miguel Montero.
But the Padres quickly tied the game in the bottom of the frame when Amarista hit a one-out triple and crossed the plate on Richard's groundout to second.
Neither team would move a runner past second base from there until the Padres' big eighth inning put them on top for good.
Amarista started the rally with a one-out bunt single that Guzman followed by hammering an outside changeup over the left-center field wall for a pinch-hit home run.
"[Guzman] was due something big," said San Diego manager Bud Black.
After Chris Denorfia's single knocked Miley out of the game, Maybin greeted new pitcher David Hernandez with a triple into the gap in left-center field.
Yonder Alonso then worked a walk before Carlos Quentin singled in Maybin. Hernandez was replaced by Brad Ziegler after a Chase Headly walk loaded the bases and Nick Hundley capped the rally going by slapping a sinking liner into right field that Upton had deflect off the tip of his glove, allowing Alonso and pinch-runner Anthony Bass to score for a 7-1 lead.
Brad Brach worked a perfect ninth to seal the win for the Padres.
"Things happened quick there in the eighth," said Bloomquist.
Both benches cleared in the eighth inning after Arizona's Chris Young was upset with Cashner for an inside pitch. No punches were thrown...Miley had won his previous three starts...Goldschmidt extended his career-best hit streak to 10 games...Arizona hit 1-for-8 with runners in scoring position and left seven men on base..Guzman's home run was his first of the season.