SAN DIEGO (AP) One series removed from getting shut out twice, the San Diego Padres offense has seldom looked better.

And the same could be said for starter Ian Kennedy.

The Padres thumped the Arizona Diamondbacks 12-2 on Wednesday night and smiles were plentiful in their jubilant locker room.

``It's been awhile since we had a game like that,'' said Jedd Gyorko, who had one of the team's three home runs. ``We had good at-bats, up and down the lineup.''

Kennedy (6-11), pitching his against his former team for the second time, was the beneficiary. He struck out seven and allowed two runs and six hits in seven innings, showing his best fastball since being acquired on July 31.

``That's the best velocity we have seen out of him all year,'' Padres manager Bud Black said. ``His arm was quick, he was painting it early and he really pitched well.''

It was Kennedy's final start of the season and 10th since the Padres traded for him. Over that span he's gone 4-2 with a 4.24 ERA.

``I've been working on some things and it has finally clicked,'' he said.

In addition to the three homers, four Padres had at least two RBIs and four finished with multiple hits.

Gyorko continued his solid season, as his 21st home run placed him one ahead of the Atlanta Braves' Evan Gattis for the major league lead among rookies. Chase Headley had three RBIs, with Gyorko and Chris Denorfia getting two each.

``I probably have the most at-bats so I should be up there in the lead,'' Gyorko said. ``But it is satisfying.''

Gyorko's two-run homer capped a four-run fifth that gave the Padres a 6-2 lead. Denorfia accounted for the other runs with a two-run single which scored Kennedy and Will Venable.

For Arizona starter Randall Delgado (5-7) that was his last inning after surrendering six runs and seven hits.

``He was throwing the ball nicely,'' Arizona catcher Miguel Montero said. ``It was really just the one homer that really hurt him, the two-run homer. The solo homers won't kill you. I thought Randall made a couple of mistakes and he paid for it.''

Diamondbacks manager Kirk Gibson said Delgado's pitch to Gyorko was misplaced.

``It was just a hanging changeup right there down the heart of the plate,'' Gibson said. ``He's just going to have to make better pitches.''

The Padres' Tommy Medica homered in the fourth to tie the score 2-2. It was Medica's third homer since being elevated from Double-A on Sept. 10 and it landed in the sand box outside the fence in center field.

``We got a little spark when Tommy hit it into the sand,'' Black said.

Medica's blast erased Kennedy's mental error in the top of that inning, one that came without him delivering a pitch.

Paul Goldschmidt opened with a double and advanced to third on Martin Prado's single. With runners at the corners, Kennedy stepped toward third on a pick-off attempt, but didn't throw the ball. Goldschmidt scored on the balk for a 2-1 lead.

``I missed the sign,'' Kennedy said. ``That was my mistake.''

The Diamondbacks had pulled even at 1 in the third when Delgado drove in Gerardo Parra with a single up the middle. Parra led off the inning with a double after Kennedy retired the first six batters.

Two doubles got the Padres a run in the first. Headley's double off Parra's glove in right-center chased home Denorfia, who was aboard after his one-out double.

Long-time Padres' minor leaguer Chris Robinson's three-run homer in the eighth was the first hit of his career, coming on his sixth major league at-bat.

``That was the highlight of the year,'' Gyorko said. ``That was awesome.''

Rene Rivera, Headley and Denorfia all had three hits for the Padres.

NOTES: Venable isn't 100 percent with his abdominal strain, but he returned to the starting lineup. Venable, who has a team-high 22 HRs, missed two games. ... SS Ronny Cedeno, who was beaned by a pitch from Heath Bell on Monday, remains out with a headache. ... Goldschmidt extended his hitting streak to 15 games with a fourth-inning double. ... Diamondbacks RHP Trevor Cahill (8-10) starts in Thursday's series finale. He's 5-0 with a 2.64 ERA since returning from a hip contusion on Aug. 17.