NEW YORK — Oliver Perez rebounded from a rough season debut and the New York Mets earned their first victory at Citi Field, beating the bumbling San Diego Padres 7-2 on Wednesday night.

Carlos Delgado homered and Perez pitched six smooth innings to help New York end San Diego's five-game winning streak. The Padres spoiled Monday night's opener at the $800 million ballpark with a 6-5 victory over the mistake-prone Mets.

After giving up eight runs and five walks in 4 1-3 innings against Cincinnati last week, Perez (1-1) held the Padres to one run and three hits. The often-erratic lefty walked only two and struck out four.

Bobby Parnell, J.J. Putz and Sean Green finished up as New York celebrated Jackie Robinson Day with a comfortable win.

One home run shy of 500, Gary Sheffield got his first start for the Mets, in right field. He went 0-for-2 with a walk and scored a run.

Making his first start in the outfield since May 16 last year with Detroit, Sheffield handled two fly balls without a problem. The 40-year-old slugger signed with the Mets on April 4, four days after he was released by the Tigers in a surprise move.

It wasn't all good news on Wednesday for the Mets, however. No. 2 starter Mike Pelfrey has tendinitis in his pitching forearm and could miss his next scheduled start Sunday against Milwaukee.

San Diego threw the ball all over the place in the seventh inning — except over the plate. Three walks, a wild pitch, a passed ball and an ugly error helped New York score four runs on one hit, a bunt single by Luis Castillo.

Luke Gregerson opened the inning by throwing 10 straight balls before he was lifted for Edward Mujica. On the next pitch, Castillo dropped a nice bunt toward third that loaded the bases.

With pinch-hitter Ryan Church facing an 0-2 count, Sheffield scored when Mujica uncorked a high wild pitch. After Church struck out and Jose Reyes was intentionally walked, Daniel Murphy's sacrifice fly made it 4-1 Mets.

Castillo scored from third on a passed ball. Reyes stole second on the same delivery and raced all the way around the bases when catcher Nick Hundley threw wildly toward the plate for an error in an attempt to get Castillo.

In the eighth, Delgado hit a leadoff homer against Luis Perdomo into the second deck in right field. It was a harsh welcome for Perdomo, who was facing his first batter in the majors.

Adrian Gonzalez homered in the ninth for the Padres, his second of the series.

New York loaded the bases with nobody out in the fourth on singles by Murphy and David Wright, plus a walk to Delgado.

Carlos Beltran hit an RBI single off starter Kevin Correia (0-1), and another run scored when Sheffield grounded into a double play.

San Diego cut it to 2-1 in the fifth on Scott Hairston's two-out RBI single.

Notes: Mets ace Johan Santana and his wife, Yasmile Garcia, had their third child on Tuesday, Johan Jr. The pitcher left the team this week to join his wife in Florida for the birth. ... Among those on hand Wednesday afternoon for the Jackie Robinson Rotunda dedication ceremony at Citi Field were Hall of Famers Frank Robinson and Joe Morgan. Jackie Robinson's widow, Rachel, and their children also attended Jackie Robinson Day ceremonies before the game. Rachel Robinson was escorted onto the field by Mets manager Jerry Manuel. ... Sheffield made six starts in left last season. He hadn't started in right since July 21, 2007. ... It was Gonzalez's 100th career home run. ... RHP Jake Peavy goes for the Padres on Thursday night against John Maine. ... New York released INF-OF Marlon Anderson.