FLUSHING, New York (Ticker) - New York Mets fans began the day cheering for Pedro Martinez and ended it with an ovation for Ramon Castro .

Castro's single with two outs in the ninth inning scored Victor Diaz and lifted the Mets to their sixth straight win, a 4-3 triumph over the Florida Marlins .

A sellout crowd of 55,351 came to Shea Stadium to watch Martinez make his first home start for the Mets. The three-time Cy Young Award winner did not disappoint, throwing seven effective innings.

"I'm very aware (of the crowd)," said Martinez, who left the world champion Boston Red Sox to sign with the Mets in the offseason. "It's nice that there were 55,000 there to see me. It wasn't just Yankee Stadium. I hope I can continue to be a ticket every time I come out."

The Mets recorded their first six-game winning streak since August 12-18, 2003. After opening the campaign with five straight losses, the Mets are above .500 for the first time this season.

"We had a big crowd out there and we're getting it done," New York's Carlos Beltran said.

The day ultimately belonged to Castro, who spent at least parts of the last six seasons with the Marlins before signing with the Mets in December.

Castro, who entered the game as a defensive replacement for Mike Piazza in the ninth, followed Diaz's two-out double in the bottom half by lining a 1-1 pitch from Florida closer Guillermo Mota (0-1) into right-center field to plate the winning run.

"Last year, I got hurt and didn't get a chance to play," said Castro, who was limited to just 32 games in 2004 due to a toe injury. "Now, the Mets are giving me that chance."

Castro's heroics ended what began as a pitchers' duel between former Met Al Leiter and Martinez.

After seven seasons with the Mets, Leiter was not re-signed by new general manager Omar Minaya during the offseason and landed with the Marlins. The New Jersey native was effective in his homecoming, allowing just one run and three hits in seven innings.

"It was a little different, which will happen anytime you come back to an old employer," Leiter said. "I'm always nervous the day I pitch. After I got through the first, I settled down."

Martinez struck out nine in seven innings to push his season total to 30 but threw three wild pitches in a game for the first time in his career. The miscues all led to Florida runs.

Martinez refused to blame Piazza, claiming he was trying to throw some of the pitches in the dirt.

"Michael did a great job," Martinez said. "I'm not the easiest pitcher to catch."

Leiter left with a 2-1 lead, but the Mets got a two-out RBI single from Beltran and a run-scoring, ground-rule double from Piazza against Todd Jones in the eighth.

Mets closer Braden Looper blew his second save opportunity in three tries in the top of the ninth.

Florida put runners on first and third on singles by Miguel Cabrera and Carlos Delgado . One out later, Cabrera tried to score on a grounder to first base and appeared to beat Piazza's tag but was called out by plate umpire Charlie Reliford.

"You (reporters) have to go out and campaign Major League Baseball for instant replay instead of all this (junk) second-guessing of umpires," Florida manager Jack McKeon said.

Juan Encarnacion followed with a double to left field to tie the game, 3-3.

Martinez struggled with his command early. Juan Pierre opened the game with a single, advanced to third on a pair of wild pitches and scored on a groundout by Luis Castillo .

Castillo raced home with a run in the fourth when Martinez struck out Carlos Delgado on a pitch in the dirt that bounced away from Piazza.

The Mets had runners on first and third with none out in the fourth but settled for just one run when Piazza grounded into a double play.