NEW YORK — Andrew Knapp thought he had caught strike three Wednesday night as he squeezed his mitt around Mark Leiter Jr.'s full-count change-up. Jose Reyes, Knapp thought, had swung and the catcher believed the third out of the 10th inning was secure.

"I thought he went," Knapp said. "I think a lot of guys go, just from my point of view. But, yeah, it's such a judgment call."

Third-base umpire Phil Cuzzi disagreed. Reyes did not swing, he said when he was asked for an opinion. That wasn't strike three in Knapp's glove. It was ball four. The inning continued, and one pitch later a 3-0 loss to the Mets was sealed.

The Phillies fell on an extra-inning home run  at Citi Field for the second time in three days. Brandon Nimmo connected on Leiter's first-pitch curveball and sent it to right-center for a three-run homer. The home plate circle, where just minutes earlier Knapp thought the inning had ended, was flooded with sunflower seeds as the Mets celebrated.

"I don't know. Maybe, he went," Leiter said. "But that's part of it and I have to get the next guy. Didn't get it. Have to give Nimmo credit. That was a great swing. Good for him."

A walk-off homer in Queens is a tough way to lose, especially twice in the same week. The Phillies had to settle for a series split with the Mets,  but they could board their train to Baltimore with the solace that they have four winnable games standing between them and the all-star break.

They will play the Orioles in Baltimore on Thursday  night before flying to Miami for three. The Phillies, even with two tough losses in three days, are still in first place, although now they are tied with the Braves after Atlanta's win Wednesday night.  And they have a chance to end the first half with some wins.

The Phillies were alive in the 10th inning only because of their pitching. The Mets did not have a batter reach second base until the eighth.

Vince Velasquez, pitching for the first time in 11 days, returned from the disabled list to pitch six shutout innings. Pat Neshek, Victor Arano, Seranthony Dominguez, and Leiter combined for the next 11 outs before Nimmo ended it.

"Vinny gave us a great chance to win that ballgame," Knapp said. "I was really proud of him."

Velasquez went toe-to-toe with Mets ace Jacob deGrom and stood his ground. He struck out three, walked one, and allowed just two hits. He had excellent command of his fastball and turned in an inspiring start.

It was the type of night Velasquez needed to silence any buzz that grew from Enyel De Los Santos' major-league debut a night earlier. It was Velasquez's first start since he was hit by a line drive on his right forearm and manager Gabe Kapler said the pitcher did "everything he could have possibly done.

"It's a pitchers' duel. It's awesome," Velasquez said. "It's a competition, just a battle. I tip my cap to him. He's been doing a great job all year. To bounce back and have a start like that today, I'm ecstatic."

The Phillies offense was silenced by deGrom for eight innings. The Mets were finally forced to open their bullpen, but the Phillies' luck would not change. They totaled six hits, left seven runners on base, and went hitless in their four chances with runners in scoring position. The offense could not do much. And the pitching could hang on for just so long.

"Super tough loss," Kapler said.