New York Mets leftfielder John Mayberry Jr. is congratulated after...

New York Mets leftfielder John Mayberry Jr. is congratulated after his walk-off single against the St. Louis Cardinals during the 14th inning of a game at Citi Field on Monday, May 18, 2015. Credit: Kathleen Malone-Van Dyke

The Mets wasted yet another gem by their ace, Matt Harvey. Then they sat through a blown save by their previously flawless closer, Jeurys Familia.

To cap it off, their slumbering offense sleepwalked deep into extra innings, unable to muster anything against the Cardinals' bullpen. By the 14th inning Monday night, the Mets appeared destined for a well-deserved defeat.

But John Mayberry Jr.'s bases-loaded infield single with one out in the 14th nudged the Mets past the Cardinals, 2-1, to the relief of a crowd that had thinned out during a marathon evening.

The Mets, weary after 4 hours, 14 minutes, spilled out onto the field. After his first walk-off hit as a member of the Mets, Mayberry wound up in the grasp of backup catcher Anthony Recker.

"It's awesome," said Mayberry, who was hitting .114 at the start of the night. "I think Recker took me halfway into rightfield."

That the Mets emerged with a victory over the Cardinals -- owners of baseball's best record at 25-13 -- was perhaps the only saving grace after Harvey's brilliance was squandered.

In a season that has been marked by a constant give-and-take -- a concession to protecting their budding ace's surgically repaired right elbow -- the Mets must decide just how much to push Harvey.

On Monday night, the answer came through crystal-clear from manager Terry Collins, who was burned five days earlier for being conservative.

On Wednesday, with a 1-0 lead over the Cubs, Collins pulled Harvey after seven scoreless innings and 100 pitches. Later, he watched as the bullpen blew the lead.

Against the Cardinals, Collins didn't summon a reliever until the ninth, turning a tense game over to Familia, who had been 13-for-13 in his save chances. It didn't work.

After one-out singles by Matt Adams and Yadier Molina put runners on first and third, Jason Heyward lifted a fly ball to shallow rightfield, deep enough for pinch runner Pete Kozma to score the tying run on the weak-armed Curtis Granderson, whose throw came in up the third-base line.

With that, Harvey's stellar night became another frustrating footnote, even though he proved equal to the task of protecting a 1-0 lead provided in the fourth on Granderson's double and Lucas Duda's single through the shift.

Harvey nearly made it stand up, overcoming early command issues to settle into a groove. He got some help from his defense when maligned shortstop Wilmer Flores made a diving stop to start a key double play. It bought enough time for Harvey to get into a rhythm.

"As the game went on, I got a little bit sharper," said Harvey, who lowered his ERA to 1.98 and equaled a career best by pushing his scoreless streak to 16 innings.

By the eighth inning, Harvey was pitching before a crowd that chanted his name. Though he had posted nothing but zeroes, he would come away without a decision.

"As a starter, you've done your job," he said. "I was obviously pretty happy."

As the game dragged on, the Mets' bullpen tacked on zeroes after Familia's blown save. Rookies Erik Goeddel and Hansel Robles passed perhaps their biggest tests thus far in high-leverage situations.

Afterward, Harvey looked at the clock and realized it had been two hours since he had last thrown a pitch. By then, his concern had long shifted away from his own performance. Now it was squarely on that of his team.

Though he was denied a victory, the Mets somehow avoided that fate.

"John Mayberry came up and got it done," Harvey said. "And a win is a win."

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