NEW YORK -- Despite being separated by 12 games in the standings, the Arizona Diamondbacks and New York Mets entered Monday both in desperate need of a win and some good fortune.

The Diamondbacks got what they needed, and the Mets didn't, in fashions that symbolize why Arizona occupies a National League wild-card spot and New York is destined for a high draft pick next June.

A terrific throw to the plate by Diamondbacks left fielder David Peralta preserved a tie in the seventh inning Monday night, and A.J. Pollock hit the go-ahead two-run homer in the 10th inning to lift Arizona to a 3-2 win over the Mets at Citi Field.

The victory was just the fourth in the past 13 games for the Diamondbacks (68-57), who moved within a half-game of the idle Colorado Rockies for the first NL wild-card spot. Arizona was assured of remaining at least 2 1/2 games ahead of the Milwaukee Brewers in the race for the second wild card. The Brewers played the San Francisco Giants later Monday.

"The team needed it," Pollock said. "Talking about the throw there -- you don't even have a chance if David doesn't make a perfect throw like that."

J.D. Martinez's RBI single in the fourth inning gave the Diamondbacks a 1-0 lead before the Mets, who stranded eight runners and six in scoring position over the first six frames, finally tied the game in the seventh.

With the bases loaded and one out, Yoenis Cespedes (3-for-5) singled to left. Travis d'Arnaud trotted home, and Mets third base coach Glenn Sherlock waved home Asdrubal Cabrera from second base.

Peralta charged the hard-hit ball by Cespedes and fired home, where catcher Chris Iannetta applied the tag a split-second before the sliding Cabrera's foot touched home plate.

"When it was hit, you're kind of thinking '2-1,'" Diamondbacks manager Torey Lovullo said. "We got the best results possible."

The play was upheld on review, much to the relief of a nervous Peralta.

"I was keeping my fingers crossed," he said with a grin.

The Diamondbacks didn't get a runner into scoring position between the fifth and ninth but went ahead in the 10th.

Pinch hitter Gregor Blanco drew a leadoff walk against Erik Goeddel (0-1). Blanco went to second on a groundout by Peralta before Pollock homered well beyond the center field wall.

Rookie Jimmie Sherfy (1-0), who was recalled from Triple-A Reno on Sunday and was making his second big league appearance, earned the win with a perfect ninth.

"We were trying to ease him into some outings," Lovullo said of Sherfy. "But he walked into a really big moment and executed."

Fernando Rodney notched his 28th save despite giving up a leadoff homer to Michael Conforto in the 10th.

Conforto was the only baserunner over the final three innings for the Mets (54-69), who have lost seven of eight to fall 15 games below .500 for the first time since Sept. 28, 2014. New York stranded 10 and had two players thrown out on the basepaths. Brandon Nimmo led off the game with a double but was caught trying to go to third on a comebacker to pitcher Taijuan Walker.

The Mets also learned of some more misfortune during the game, when the team announced left-handed pitcher Steven Matz will undergo season-ending surgery to reposition the ulnar nerve in his left elbow.

Matz and the Mets insisted he was pitching through normal soreness even as he went 0-6 with a 10.19 ERA in his past eight starts. Matz, who had Tommy John surgery in 2010 and had bone chips removed last October, said he underwent a nerve test earlier Monday that alleviated elbow discomfort and indicated the nerve was the issue.

"It's definitely nice to have an answer," Matz said. "The doctor told me that if you feel relief from this, then that's something to put our finger on. When I got up after the injection, I felt fine."

Several pitchers who have undergone Tommy John surgery, including teammates Goeddel and Jacob deGrom, have required ulnar nerve surgery and come back to pitch successfully.

"We're certainly very optimistic that that might be an answer that we've been looking for," Mets manager Terry Collins said.

Walker allowed seven hits and one walk while striking out four over 5 1/3 scoreless innings. Mets starter Robert Gsellman gave up one run on five hits and one walk while striking out three over 6 1/3 innings.

NOTES: Mets RHP Matt Harvey (shoulder) made his third rehab start Monday, when he allowed two runs over three innings for Double-A Binghamton. ... Mets RHP Robert Gsellman pitched into the seventh inning for just the fourth time in 16 starts this season. ... The Diamondbacks recalled RHP Matt Koch from Triple-A Reno. He replaces RHP Braden Shipley, who was optioned to Reno following the team's Sunday game. ... Diamondbacks OF Yasmany Tomas (core muscle) is scheduled to undergo season-ending surgery Tuesday.