The New York Mets are desperately trying to hold on in a rapidly tightening division — and trying just as desperately to avoid a historic late-season collapse.

John Maine squandered a big lead and the Mets’ losing streak reached five games last night when their ninth-inning rally fell short in a 9-8 loss to the Nationals. The loss stung all the more when Philadelphia outlasted the St. Louis Cardinals 7-4 in 14 innings.

The Phillies, who were seven games back after losing last Wednesday, have won six straight to get within 1½ games of the NL East leaders. It’s their smallest deficit since opening day, and the Mets’ smallest lead since a 1½-game advantage over Atlanta after games of July 16.

“We made steps in the right direction,” the Mets’ David Wright said. “It wasn’t enough.”

No major league team has failed to finish in first place after leading by seven games so late in the season, and only two others — the 1938 Pittsburgh Pirates and the 1934 New York Giants — failed to finish in first place after having a seven-game lead in September.

“At this point of the season, every game is magnified,” Rod Barajas, who drove in the tiebreaking run for Philadelphia, said.

While the Mets have controlled their division most of the season, the lead in the NL Central continues to change hands almost daily.

After Ben Sheets left with tightness in his left hamstring, the Milwaukee bullpen shut down Houston in a 9-1 victory that pushed the Brewers less than a percentage point ahead of Chicago. The Cubs lost to Cincinnati 5-2.

“If Milwaukee wins every game the rest of the way, they’re going to win, plain and simple,” the Cubs manager, Lou Piniella, said.

In other NL games, it was Arizona 5, San Francisco 0; San Diego 5, Pittsburgh 3 and Atlanta 4, Florida 3. Colorado took both games of a doubleheader from Los Angeles, beating the Dodgers 3-1 in the opener and 9-8 in the nightcap.

Mike Maroth (0-5) was the 11th pitcher used by St. Louis against the Phillies, an NL record. The Cardinals also tied an NL record with 28 players used in an extra-inning game and the combined 53 players used by both teams tied the NL mark for an extra-inning game.

“We stayed there long enough to win,” manager Charlie Manuel said.

Chase Utley singled to start the 14th, moved up on a sacrifice and scored the go-ahead run.

Clay Condrey, who allowed five runs and got no outs in Monday’s 13-11 victory, earned his first career save. Jose Mesa (1-2) struck out two in two innings.

“You never want to play five hours and come up on the losing end, use up a whole bullpen and use up pretty much everybody on the bench,” Condrey said. “To come away with a win, I hope it lifts us up even higher.”

The Mets, meanwhile, just keep sinking lower.

After making 10 errors in a two-game span, New York staked Maine (14-10) to leads of 4-0 and 7-3 before things unraveled. Ronnie Belliard’s three-run homer capped a five-run fifth that gave Washington an 8-7 lead, and pinch-hitter D’Angelo Jimenez added a solo shot in the sixth.

The Mets got 16 hits, three in the ninth when they scored once against closer Chad Cordero to make it 9-8. But pinch-hitter Ruben Gotay struck out with runners at the corners to end it.

Jesus Colome (5-1), the fourth of nine Nationals pitchers, worked a scoreless sixth for the win. Cordero earned his 35th save in 44 chances.

“Everyone did their job but me,” Maine said. “I didn’t hold my end up.”