Fernando Tatis hit a three-run homer and the Mets staked Pedro Martinez to a seven-run cushion. 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.
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, manager Charlie Manuel turned to pitcher Brett Myers to bat for Rudy Seanez. Myers struck out looking.
Coste then drove one to center way over the head of the drawn-in Carlos Beltran.
Seanez (5-3) pitched a scoreless 13th for the win.
The Mets used four relievers to get to the ninth after Pedro Martinez lasted five innings. But Luis Ayala couldn't protect a one-run lead.
Ayala, who converted his other save chance since joining the Mets in a trade with Washington last week, got the first two outs. But Werth singled and pinch-hitter Bruntlett, the last position player available for Philadelphia, drove him in with a double to right-center.
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.
Jamie Moyer lasted just three innings in his shortest outing in three years. The 45-year-old left-hander gave up six runs and nine hits. Moyer had been outstanding recently, not giving up more than three runs in 14 straight starts since June 1.
Tatis, who has resurrected his career after spending three of the last four seasons out of baseball, gave the Mets a 6-0 lead when he connected in the third inning.
Damion Easley was 4-for-5 with a homer for the Mets, who trailed the Phillies by 7½ games on June 13. New York is 39-25 since Jerry Manuel replaced Willie Randolph as manager.
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.
Trailing 7-1, the Phillies stared their comeback in the fifth. Relief pitcher Clay Condrey led off with a broken-bat double down the left-field line for his first career extra-base hit.
Rollins then ripped a liner to the seats in right to cut it to 7-3. Howard hit an opposite-field, two-run drive to left to get the Phillies within 7-5.
Rollins' RBI single cut it to 7-6 and put runners on first and third with one out in the eighth. Booed throughout the homestand for calling fans "frontrunners" in a television interview two weeks ago, Rollins got a standing ovation when he came to the plate that inning.
A sellout crowd of 45,204 at Citizens Bank Park included many Mets fans who had reason to cheer right from the start.