SAN DIEGO — The Padres were excited by Ian Kennedy's first two starts with San Diego after he was acquired from Arizona.
But on Friday night, Kennedy looked more like the pitcher who struggled all season with the Diamondbacks than the one who won 21 games in 2011.
Kennedy allowed three home runs and failed to finish the fifth inning in a 5-2 loss to the New York Mets.
Marlon Byrd and Ike Davis connected on consecutive pitches from Kennedy (4-9) in the third. Daniel Murphy hit a two-run shot an inning later to give the Mets a 5-1 lead.
"They talk about pitching here (Petco Park)," Kennedy said. "Well, it doesn't matter if you make mistakes anywhere, they go out. They really got me. They turned on the ball pretty quick."
Davis has four homers off Kennedy in nine at-bats.
"It wasn't that his stuff wasn't crisp," Padres manager Bud Black said. "The fastball location wasn't where it was in Cincinnati five days ago."
Kennedy, acquired in a trade on July 31, allowed five runs and seven hits over 4 2-3 innings in his third start for San Diego. The right-hander, who has allowed 22 home runs, struck out seven and walked four.
"I wasn't as sharp as I wanted to be command-wise all night, which explains why there were so many home runs," Kennedy said.
Jonathon Niese (5-6) gave up one run and six hits over six innings in his second start since returning from the disabled list. Niese struck out a season-high nine and walked one with one hit batter. He and three relievers combined to strike out 13, running New York's two-game total in San Diego to 28.
LaTroy Hawkins pitched the ninth for his fourth save while filling in for injured closer Bobby Parnell.
Byrd has driven in six runs in his last three games after going without an RBI for the previous 13. Before he homered, Murphy had just one extra-base hit in his last 20 games.
New York catcher Anthony Recker, starting after John Buck went on the paternity list, had a career-best three hits and also reached on a walk.
San Diego has dropped eight of 10 and fell into last place in the NL West.
Byrd led off the third inning with his 19th home run and, on the next pitch, Davis hit his seventh. It was only the second time this season that New York has hit consecutive home runs.
Davis, who has had a second-half resurgence, hit his second homer since he was recalled from the minors on July 5.
"I finally caught up to one and drove it out of the yard," he said. "To be honest, it felt good. I have been getting jammed with fastballs in lately, and I finally got to one."
Will Venable ran his career-high hitting streak to 13 games with a solo homer in the third. Venable's 16th home run extended his career high.
Yonder Alonso added an RBI single in the eighth and Jedd Gyorko had three hits for San Diego, including a double. Gyorko has nine hits in his last six games, six for extra bases.
NOTES: Kennedy dropped to 4-1 against the Mets in six career starts. ... Padres LF Carlos Quentin is expected to miss another seven to 10 days with a strained right knee. Quentin received a second opinion from the Kerlan-Jobe Orthopaedic Clinic in Los Angeles on Thursday and San Diego manager Bud Black said the result was "the same findings that our team doctors had." ... Slumping New York rookie CF Juan Lagares was held out of the starting lineup. Lagares is hitting .210 (13 for 62) in August and is hitless in his last 13 at-bats with five strikeouts. ... The teams continue their four-game series Saturday night with Mets RHP Jenrry Mejia (1-2, 2.22 ERA) set to face Padres RHP Edinson Volquez (8-10).