The National League wild-card race got a little tighter last night, thanks to the determination of Mets’ and fill-in catcher Ramon Castro.

Disgusted by his first two at-bats against Philadelphia, Castro turned his night around with a pair of extra-base hits, fueling a furious Mets comeback that resulted in a 6-4 victory and cost the Phillies the outright lead in the NL wild-card chase.

Castro doubled and scored in the seventh inning and then hit a three-run homer to put the Mets in front in the eighth. Braden Looper’s 28th save sealed the win and dropped the Phillies (70-62) into a wild-card tie with the Florida Marlins, who beat St. Louis 7-6.

The Mets and Houston Astros (both 69-62) are a half-game back.

“Playing from behind, winning games, that’s good for us,” said Castro, who hit his sixth home run. “We always feel confident. Playing from behind, that’s a big part of the game.”

Castro struck out and popped out in his first two swings against starter Robinson Tejeda.

“I was a little down after those two at-bats,” he said. “But I thought, ‘I’ve got three more chances.’ “

He only needed two.

With the Mets trailing 4-2, Castro opened the seventh with a double and scored on a wild pitch by reliever Ryan Madson. That made it 4-3 and put the Mets in striking distance when David Wright opened the eighth with a walk against Ugueth Urbina (3-1).

Wright hustled down the line, as if he knew something good was about to happen for the Mets.

“We have tremendous confidence in each other,” he said.

After rookie Mike Jacobs struck out, Victor Diaz walked, bringing up Castro.

“The first pitch, he showed me a fastball,” Castro said. “I was looking for something off-speed after that.”

He hit a slider into the left-field seats, capping New York’s comeback.

“They beat me,” Urbina said. “They didn’t beat anybody else. They beat me. I made a mistake and they got me.”

The Mets had trailed from the start after Kenny Lofton hit his first home run since opening day and Pat Burrell added a two-run shot in the first inning against Mets starter Jae Seo. New York pecked away at the lead, as Carlos Beltran drove in a pair of runs with his 14th home run and a fifth-inning single.

Castro took care of the rest of the comeback with his seventh-inning double and eighth-inning homer, which set off a big celebration. With Mets shortstop Jose Reyes jumping in front of the dugout, Castro came out for a curtain call from the crowd of 36,505 that came to Shea Stadium for the Mets’ return from a seven-game road trip and their most meaningful late-season home game in several years.

Juan Padilla (1-0) got the win.