SAN DIEGO (AP) -- May hasn't been kind to Ian Kennedy.
The San Diego Padres right-hander lost his fourth straight start Thursday night, surrendering three home runs in the first three innings of an 11-5 defeat to the Pittsburgh Pirates.
"We've had a good run of starts here and this was a severe bump in the road for our rotation," manager Bud Black said. "Nobody feels worse than Ian about this one. He just got some pitches elevated and they didn't miss them from the first inning on."
Jung Ho Kang hit a three-run homer, and Starling Marte and Gregory Polanco also went deep off Kennedy.
Kennedy (2-5) was chased by Andrew McCutchen's RBI double with two outs in the fourth. He lost his fourth straight start, allowing seven hits and seven runs, striking out five and walking two. Kennedy has allowed seven homers and 20 earned runs in his last four starts.
"It's been a roller-coaster for Ian this year," Black said. "We're trying to work through that. We're trying to get the consistency from Ian, and Ian's trying to do everything he can to string together some good starts."
"It's really frustrating," Kennedy said. "Fastball command was all over the place. They hit a couple of breaking balls for homers. It's really, really frustrating, really inconsistent, not what I like to do. As a pitcher, you try to go out there and be as consistent as possible. This has been a real test so far, the first month or so that I've pitched."
A.J. Burnett (5-1), who no-hit the Padres in 2001 while with the Marlins, won his fifth straight start. McCutchen, Neil Walker and Francisco Cervelli each had three of the Pirates' 15 hits.
The Pirates' first six runs scored on homers, including no-doubters by Kang and Polanco. Kang's shot with two outs in the first, his third, went an estimated 430 feet into the second deck in left field. Polanco led off the second with a 414-foot homer to center, his second.
Marte hit a two-run shot in the third, his 10th. McCutchen was aboard on a leadoff single.
Burnett allowed five runs, four earned, on eight hits in 5 2-3 innings, struck out six and walked two.
Josh Harrison and McCutchen hit RBI doubles in the four-run sixth and two runs scored on shortstop Alexi Amarista's throwing error.
Padres: RHP Brandon Morrow, on the DL with right shoulder inflammation, threw 45 pitches in a simulated game. He'll throw again during the weekend and if all goes well, could be sent out for a rehab start.
Pirates: LHP Francisco Liriano (2-4, 3.86) is 1-2 with a 2.42 ERA in four career starts against San Diego.
Padres: Ace James Shields (6-0, 3.75) makes his first career start against the Pirates.