MLB

Mets suffer grand letdown after game-tying homer in ninth

Jason Bay has seen his share of misfortune since joining the Mets prior to last year, but neither he — nor anyone else — ever has seen anything like what the team has gone through the past two games.

On Sunday, Scott Hairston hit a game-tying homer with two outs in the top of the ninth in Washington before the Mets lost in the bottom of the inning.

Last night, Lucas Duda’s two-run shot in the bottom of the ninth knotted the game against the Marlins, but the Mets lost 7-3 in 10 innings after Jason Isringhausen gave up a grand slam to Mike Stanton.

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“You’d think in a perfect world that at least one of the two games we tied we’d get momentum,” Bay said. “You’d like to at least win one of them and hopefully two when you’ve got that type of comeback.”

Not the Mets.

Instead, Daniel Murphy’s mental miscue in the 10th, when he held on to the ball too long in a rundown and allowed Dewayne Wise to scramble back to first after rounding nearly halfway to second, forced Isringhausen to pitch to Stanton with the bases loaded.

“He’s been hot lately and after I went to 3-2, I had to pitch to him,” said Isringhausen, the newly installed closer who took his first loss of the season. “I threw him a cutter and missed my spot.”

Stanton made him pay, making the possibility of the Mets (55-54) staying in wild-card contention even more unrealistic. Earlier in the day, general manager Sandy Alderson said he spent the weekend hunkered down in his Citi Field office prior to Sunday’s trade deadline in an effort not to dismantle the team, but to add middle-relief help.

“We decided to keep them together,” Alderson said. “They did well in the immediate aftermath of the [Carlos] Beltran trade. Frankly, we felt it was in the best interest of the organization to play well the rest of this season than it was to add a modest prospect or two in small deals.”

Manager Terry Collins thinks the Mets need at least 90 wins to have a chance at the wild card.

Alderson said if a significant player became available, the Mets could increase their payroll, but cautioned he would not make anything “dramatic” trades and made it clear he’s “not trolling for players.”

“If it happens, it happens, but don’t expect it to happen anytime soon,” he said. “We’ll see how things go.”

The past two games, they have been excrutiating.

The Mets were unimpressive for most of last night’s game, with Mike Pelfrey failing to beat the Marlins for the 15th consecutive start — and unable to build on his last start, a complete-game victory in Cincinnati.

There was a costly throwing error from David Wright, playing his first game at home since mid-May, and Jose Reyes being thrown out at home by 10 feet by Stanton in the fifth after third-base coach Chip Hale inexplicably waved him around.

They remain 7½ games back of Atlanta for the wild card, but time is fleeting.

“The whole time we were winning games after Carlos got traded, we were just playing ball and not thinking, ‘We have to win,’ ” said Bay, who hit his seventh homer. “When you put pressure on yourself, you start pressing. We have to go back to just playing, regardless of who we’ve got.”

dan.martin@nypost.com