The Mets are playing as if it’s September.

Last September, that is.

New York’s beleaguered bullpen blew yet another big lead as the Philadelphia Phillies rallied from a seven-run deficit to beat the Mets 8-7 in 13 innings on Tuesday night.

“We stayed after them,” Phillies manager Charlie Manuel said. “A lot of things happened, everything except a fight.”

At Philadelphia, Fernando Tatis hit a three-run homer and the Mets staked Pedro Martinez to a 7-0 lead. But the Phillies chipped away against Martinez and rallied against a bullpen that has blown 10 leads in the ninth inning, according to Stats LLC.

The Mets have 22 blown saves overall, including seven by injured All-Star closer Billy Wagner. This one might have been the most devastating.

“People are going to have to get people out,” Mets manager Jerry Manuel said. “We’ll keep doing it until we find the right way.”

The Mets blew a seven-game lead with 17 remaining last season, losing the division to the Phillies on the final day. The teams meet four more times, including a three-game series at Shea Stadium next weekend.

In this one, Ryan Howard hit his league-leading 35th homer and Jimmy Rollins was 5-for-7 with a two-run shot for Philadelphia, which moved a half-game ahead of the Mets with its ninth win in 11 games.

The last time the Mets had a lead of seven or more runs and failed to win was May 13, 2003, according to the Elias Sports Bureau. They led that one 7-0 and lost 9-8 at Colorado.

Shane Victorino lined a triple down the right-field line to start Philadelphia’s 13th against Scott Schoeneweis (2-3). After Jayson Werth and Eric Bruntlett were intentionally walked, Myers was called upon to bat for Rudy Seanez. Myers, the second starting pitcher to pinch-hit for Philadelphia, struck out looking at a 3-2 pitch after being instructed not to swing.

Myers did his best in the batter’s box to distract Schoeneweis, digging in, bailing out and looking pitches all the way into the catcher’s mitt.

“I think the whole ballpark knew he wasn’t going to swing, but he put on a good show,” Coste said. “It was intimidating in the on-deck circle.”

Coste then drove one to center way over the head of the drawn-in Carlos Beltran for his first career game-winning hit at any level. He finished 4-for-4, despite entering the game in the eighth inning.

Seanez (5-3) pitched a scoreless 13th for the win.

The Mets used four relievers to get to the ninth after Martinez lasted five innings. But Luis Ayala couldn’t protect a one-run lead.

Martinez allowed five runs and seven hits in five innings, striking out eight. The three-time Cy Young Award winner, who once had an overpowering fastball, relied heavily on offspeed pitches and didn’t throw harder than 88 mph.

“It’s frustrating, but with this team, in this stadium, you never know,” Martinez said. “They never give up, especially in this band box.”

Padres 9,  Diamondbacks 2

Brian Giles and Kevin Kouzmanoff both drove in three runs as host San Diego denied Brandon Webb his 20th victory.

Webb (19-5) lost in his first bid to become the NL’s first 20-game winner since 2005, allowing six runs and nine hits in 4 2-3 innings.

The Diamondbacks retained their three-game lead over the Los Angeles Dodgers in the NL West.

Cubs 14, Pirates 9

Geovany Soto drove in seven runs and visiting Chicago overcame Alfonso Soriano’s second dropped fly ball in Pittsburgh this season.

The Cubs won their fourth straight to move 32 games above .500 for the first time since they were 90-58 on Sept. 15, 1984.

Soto had two three-run doubles and hit his 20th homer off Denny Bautista in the sixth. Derrek Lee added two RBIs and Soriano had three hits despite making a second defensive gaffe in PNC Park.

Braves 10, Marlins 9

Yunel Escobar’s single capped host Atlanta’s four-run ninth against Florida closer Kevin Gregg.

With the bases loaded and one out, Gregor Blanco grounded into what could have been a game-ending double play, but shortstop Hanley Ramirez was unable to pull the ball from his glove as Mark Kotsay slid into second, and Jeff Francoeur scored to make it 9-all.

Escobar then singled into shallow right field against Gregg (6-7), who has eight blown saves in 37 chances.

Brewers 12, Cardinals 0

Ben Sheets worked six scoreless innings and Ryan Braun was 3-for-5 with a two-run homer for visiting Milwaukee.

Prince Fielder had three hits and two RBIs for the Brewers, who have won seven straight over the Cardinals. Craig Counsell doubled twice and had three hits as the Brewers moved 22 games above .500 for the first time since they were 92-70 at the end of the 1992 season.

Braun is batting .491 with seven homers and 13 RBIs against the Cardinals this season and is a .434 career hitter against St. Louis. He is 6-for-8 against St. Louis starter Todd Wellemeyer (11-5).

Nationals 2, Dodgers 1

Nationals third baseman Ryan Zimmerman started four double plays and visiting Los Angeles matched its season high with a fifth straight loss.

The Dodgers have lost seven of eight and are 0-5 midway through a 10-game road trip. They have lost a season-high seven straight road games and have fallen two games below .500.

Derek Lowe (10-11) took the loss despite allowing only six hits in an eight-inning complete game.

Reds 2, Astros 1

At Houston, Bronson Arroyo pitched Cincinnati’s first complete game of the season and Ryan Hanigan hit a solo homer.

Hanigan broke a 1-1 tie in the eighth with a one-out homer off Geoff Geary that bounced off the facade in left center, just above the yellow line. Second-base umpire Ted Barrett made the home run signal and Houston manager Cecil Cooper came out to talk to him.

Baseball announced Tuesday it will start using video to clarify “boundary calls,” including whether fly balls went over the fence, but the system won’t start until Thursday. All Cooper could do in this one was protest to no avail.

Arroyo (12-10) allowed five hits and struck out three for his first complete game since May 16, 2007. He snapped a four-game losing streak to Houston.

Rockies 7, Giants 2

At San Francisco, Chris Iannetta and Garrett Atkins drove in two runs apiece and Jorge De La Rosa pitched six strong innings for Colorado, which has won nine of 11.

De La Rosa (7-7) allowed two runs and five hits to win for the fourth time in his last six decisions.