The collapse is complete. When the Mets needed a big game, Tom Glavine pitched one of his worst. After blowing a big September lead in the NL East, the Mets missed the playoffs Sunday when Glavine was tagged for seven runs during the first inning of a season ending 8-1 loss to the Florida Marlins.

New York’s loss coupled with Philadelphia’s 6-1 win over Washington gave the division title to the Phillies and sent the stunned Mets home for the winter wondering how they squandered a seven-game cushion over the final 18 days of an excruciating season.

Now, David Wright, Carlos Beltran, Pedro Martinez, and the rest of this talented team will forever be remembered alongside the 1964 Phillies and other famous failures for skidding to one of baseball’s most monumental collapses. To make it worse, start slugger Carlos Delgado broke a hand in the first inning when he was hit by a pitch.

No major league team had owned a lead of seven games or more with 17 to play and failed to finish in first place. New York, which had that margin on September 12, matched the largest lead blown in September. The 1938 Pittsburgh Pirates (September 1) and 1934 New York Giants (September 6) also led by seven games in the final month only to tailspin.

Philadelphia swept a three-game series at Shea Stadium from September 14–16 — giving the Phillies wins in the final eight meetings between the teams this year. That started a slide the Mets never recovered from.

Doomed by inadequate starting pitching and a leaky, exhausted bullpen, New York lost 12 of its last 17 games, committing 21 errors in the process.

Luis Castillo struck out to end New York’s latest lackluster defeat against a second-division club, prompting the last round of boos at Shea Stadium this year.

Moments later, the final in Philadelphia was posted on the outof-town scoreboard and Mets fans filed for the exits, quietly muttering to themselves.

It was one of the darkest days for a franchise that prided itself on late-season comebacks in 1969, 1973 and in the 1986 World Series against Boston.

Last year, the Mets advanced to Game 7 of the NL championship series before losing 3–1 to St. Louis. Beltran struck out with the bases loaded in the bottom of the ninth inning, a sudden end to a thrilling season.

This time, the pain was drawn out over 2 1 /2 weeks of wretched play — and the finale was a wash from the first inning on.

After squandering their cushion, the Mets fell a game behind Philadelphia with their fifth straight loss Friday night. But they bounced back when John Maine nearly pitched the club’s first nohitter Saturday in a fight-filled rout of Florida, which pulled them back into a tie for first when the Phillies lost to the Nationals.

That put the Mets’ fate back in their own hands and gave them hope that their massive slide was over.

The 300-game winner put his team in a huge hole this time, chased after getting only one out and charged with all seven of Florida’s early runs. He made a throwing error and hit Marlins lefty Dontrelle Willis with a pitch with the bases loaded, mistakes that symbolized the Mets’ late collapse.

The seven runs matched the most Glavine (13–8) allowed in an inning during his 21 years in the majors, the Elias Sports Bureau said. He also gave up seven to Colorado in 1996.

It also was the second-shortest start of his brilliant career — and perhaps his last.

The 41-year-old left-hander is contemplating retirement, or he might choose to pitch elsewhere next season. Glavine, also roughed up in a 10–9 loss to Washington on Tuesday night, has a $13 million player option for next year with a $3 million buyout.

The Mets nearly got back in the game right away, though they lost first baseman Carlos Delgado to a broken left hand when he was hit by a pitch.

New York scored in the bottom of the first on Willis’s wild pitch and had the bases loaded when Ramon Castro hit a long drive to left field. Thinking it was gone, Castro raised his index finger in the air. But Cody Ross made the catch on the warning track and let out a deep breath.

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YANKEES 10, ORIOLES 4 Alex Rodriguez raised his major league-leading RBIs total to 156, Jorge Posada took over from Joe Torre as manager for the day and the Yankees prepped for the playoffs by beating the Baltimore Orioles 10–4 on yesterday. As the wildcard Yankees made plans for their postseason opener Thursday at Cleveland, Posada and second baseman Robinson Cano did not play. Rodriguez, Derek Jeter and Johnny Damon were all lifted in the fourth inning. Chien Ming-Wang and Andy Pettitte will start the first two games for the Yankees against C.C. Sabathia and Fausto Carmona.