PHOENIX (AP) — Chase Anderson recovered after struggling early, tossing three scoreless innings.
Once Arizona's rookie right-hander reached the fifth inning, any momentum he had was gone.
Anderson gave up two runs in the first inning and a three-run homer to Yasmani Grandal in the fifth, sending the Diamondbacks to a 7-4 loss to the San Diego Padres on Sunday.
"I kind of lost the feel in that fifth inning. I can't really tell you why," Anderson said. "I felt good, my command and my fastball was coming back in the third and fourth inning — no rhyme or reason. Just have to work on it."
Padres starter Ian Kennedy (10-11) was strong in his return to Chase Field.
The right-hander struggled in his first game back in the desert a year ago, but pitched into the sixth inning and struck out six to beat his former team.
Grandal provided plenty of support, hitting a deep sacrifice fly in the first inning and clearing the wall easily in the fifth with a three-run homer off Anderson (7-6).
Pinch-hitter Will Venable added a two-run homer and Joaquin Benoit worked a perfect ninth for his eighth save to give San Diego manager Bud Black his 600th career win.
"It was a little different my first time, but this time was no different," Kennedy said. "I've been a Padre for over a year now and it kind of goes away."
Arizona fell behind early when the Padres hit Anderson hard and never fully recovered. Cliff Pennington hit a solo homer and Miguel Montero had a two-run single for the Diamondbacks, who went 1 for 6 with runners in scoring position.
"We had opportunities," Diamondbacks manager Kirk Gibson said. "We left 10 guys out there today. They got more of their guys in than we did."
Kennedy pitched at Chase Field for the first time since the trade last Aug. 27, but didn't factor in the decision after allowing six runs on six hits in 4 2-3 innings.
Kennedy was sharp early against the Diamondbacks this time, striking out five the first four innings. He made a couple of pitches he would have liked back in the sixth inning, allowing Arizona to load the bases before Montero lined a two-run single up the middle.
Ender Inciarte chased Kennedy with a run-scoring double in the sixth inning that cut San Diego's lead to 5-3.
Kennedy allowed three runs on eight hits.
"He had really good command today," Gibson said. "His breaking ball and his change-up, he mixed it in good."
Anderson had the shortest outing of his career the last time out, allowing six runs on six hits in two innings of an 8-1 loss to Washington on Tuesday.
The Padres hit the rookie right-hander hard in the first two innings, scoring a pair of runs in the opening frame on (Seth) Smith's groundout and a sacrifice fly by Grandal.
Anderson settled down for a few innings, then walked three in the third to set up Grandal's 11th home, a three-run shot that put the Padres up 5-0.
Anderson allowed five runs — four earned — on six hits and struck out five in five innings.
Black joined select company by becoming the second San Diego manager to win 600 games, though didn't know about the milestone until he was told after the game.
"It's a tribute to the players, the coaches, the organization," Black said. "It's a round number. I like 601 better."
Black is second on the Padres' all-time list behind the 951 games Bruce Bochy won with San Diego from 1995-2006.
MONTERO VS. SAN DIEGO
Monetro went 1 for 4 on Sunday, extending his hitting streak against the Padres to nine games. He's 11 for 32 with 10 RBIs in that span and also has a seven-game hitting streak at Chase Field.
Diamondbacks: INF Chris Owings played second base Saturday night while going 2 for 4 at the plate in a rehab game with Triple-A Reno. He has been a shortstop, but the Diamondbacks are taking a look at him playing second.
Padres: LHP Eric Stults, Monday's starter against Milwaukee, has allowed three or fewer earned runs in 10 of his last 11 starts.
Diamondbacks: The Diamondbacks have a day off before starting a two-game series against the Los Angeles Dodgers. RHP Trevor Cahill start on Tuesday after going 2-0 with a 2.33 ERA his past four starts.