SAN DIEGO (AP) — Bronson Arroyo made it easy for his teammates to relax at the plate, and the Cincinnati Reds broke out of their offensive slump in an unexpected way.

With Arroyo tossing a three-hit shutout, the Reds hit three home runs at pitcher-friendly Petco Park to snap a three-game losing streak with a 6-0 win over the San Diego Padres Friday night.

Cincinnati has gotten great starting pitching through the first nine games of its 11-game road trip. But the offense has been struggling often.

Ryan Hanigan and rookies Todd Frazier and Zack Cozart each homered at Petco Park, the toughest ballpark to homer at in the majors.

“Everybody knows the past week or so, we haven’t been putting runs on the board,” Cozart said. “The pitchers have been keeping us in the game. For us to give Bronson a cushion, it’s big.”

Two of the Reds’ homers barely made it into the stands. Cozart’s homer leading off the game and Hanigan’s two-run shot in the seventh both landed in the first row of the left field stands.

Frazier hit a two-run shot off Miles Mikolas in the eighth inning.

“You just keep swinging and good things happen and it did happen,” Cincinnati manager Dusty Baker said. “You can’t keep a good team down forever.”

On this night, Arroyo (4-5) was so solid, he didn’t need more than Cozart’s second leadoff homer of the season.

The righty threw his first complete game of the season, retiring 14 of the final 15 batters for the Reds’ fifth shutout, but the first solo effort by a starting pitcher.

“It couldn’t be better for everybody,” Arroyo said. “We’ve been on a little bit of a skid. It’s nice to hang in there long enough for us to get the extra two from (Hanigan). It gave me some breathing room there.”

Arroyo allowed singles to rookie Yasmani Grandal, Will Venable and Chase Headley while striking out eight and walking one.

San Diego, which had its season-high six-game win streak snapped, had only one runner reach second base.

“All of his breaking stuff and changeups came in at different speeds, so it was tough to make the adjustments,” Venable said. “He had a good feel for his stuff and made all the pitches he needed to.”

Through nine games of the road trip, the Reds’ starting pitchers have an ERA of 1.72. Arroyo became the third Cincinnati starter on the road trip — along with Mike Leake and Mat Latos — to throw a complete game.

It was Arroyo’s 13th career complete game and fifth career shutout. The last for each came on September 21, 2011 against Houston.

Cincinnati scored more than one run for the first time in four games and had scored three runs or less on the first nine games of the trip before Friday night.

“It’s nice to have that cushion,” Arroyo said about the runs the Reds tacked on.

Cozart homered on a full-count pitch leading off the game against Kip Wells (1-2) for his ninth homer. It was Cozart’s second leadoff homer this season.

“ I was a little erratic as far as trying to get a good feel for where I was,” Wells said. “(Cozart) just smashed a fastball that was elevated.”

After a leadoff walk to Todd Frazier in the seventh, Hanigan hit a two-run homer off Wells.

Wells, facing the Reds for first time since they released him in April 2010, allowed three runs on seven hits and was pulled after Hanigan’s home run.

Wells, making his second start since being recalled from Triple-A Tucson on June 26, was trying to win back-to-back starts for the first time since Aug. 8 and 14, 2007, when he was with St. Louis.

Cincinnati’s Drew Stubbs doubled in the ninth inning to snap his career-high hitless streak of 32 at-bats. Stubbs last hit was a game-winning homer on June 26 against Milwaukee’s John Axford.

NOTES: Arroyo also pitched a complete game against the Padres at Petco Park on May 16, 2007, but lost 3-2 when he walked in the winning run in the ninth inning. . Arroyo had a 1-4 record with a 6.09 ERA in his previous six road starts. … San Diego has been shut out eight times. … Reds 3B Scott Rolen, who hasn’t played since he left Sunday’s game with back spasms, was available to pinch hit Friday night and could be back in the starting lineup Saturday, Baker said. … San Diego RHP Jason Marquis will pitch on three days’ rest Sunday in place of RHP Ross Ohlendorf. … Padres RHP Andrew Cashner, on the DL since Wednesday with a strained right lat, had an MRI on Friday. Manager Bud Black said he expects Cashner to be out at least one month. … Reds RHP Homer Bailey (6-6, 4.24) will face Padres LHP Clayton Richard (6-8, 3.64) on Sunday in the series finale.