Mets pitcher Tylor Megill reacts after giving up a walk-off...

Mets pitcher Tylor Megill reacts after giving up a walk-off single to Nick Castellanos of the Philadelphia Phillies in Game 2 of the NLDS at Citizens Bank Park in Philadelphia on Sunday. Credit: Newsday/J. Conrad Williams Jr.

PHILADELPHIA — The pitch that ended Game 2 of the NL Division Series was a slider from Tylor Megill to Nick Castellanos in the bottom of the ninth, down and in but not enough of either. Castellanos lined it to leftfield. Trea Turner scored easily from second base. The Mets lost to the Phillies, 7-6, on Sunday evening.

The pitch that changed the game, though, was a fastball from Luis Severino to Bryce Harper in the bottom of the sixth, when the Mets and their standout righthander were in control of the day and the series. Moments earlier, pitching coach Jeremy Hefner visited the mound with a dual purpose: to allow a sweating Severino, near the end of his outing, to catch his breath and to tell him how to handle Harper, the Phillies’ best player, in this particular spot.

Give him nothing. Don’t let him beat you. Deal with the next guy if you must.

Severino was successful in that — until he wasn’t. Pitch one was a sinker well outside for a ball. Pitch two, another sinker low for a foul ball. Pitch three, sinker outside for another foul to get him ahead 1-and-2. Pitch four, a fastball up and away for an obvious ball.

Pitch five was a fastball, his hardest of the day at 99 mph. Severino tried to place it up and away. It ended up middle-middle — and Harper crushed it an estimated 431 feet. It ricocheted hard off the ivy batter’s eye in centerfield.

The Citizens Bank Park crowd of 45,679 — which had started to turn on the Phillies, booing their favorites repeatedly and in one instance jeering when a batter refrained from swinging at a ball in the dirt — came alive again, back to rooting for their own team. For the first time all day, it felt as if the Phillies had a chance.

Against a player like Harper, Severino said, a pitcher must locate his pitches. “It doesn’t matter how hard you throw it,” he said. “They hit it back even harder.”

 

Harper’s swing set off a wild series of events that ultimately yielded heartbreak for the Mets, evening the NLDS at 1-1. The best-of-five has become a best-of-three as the series shifts to New York, with Game 3 set for a 5:08 p.m. first pitch on Tuesday.

The Mets and Phillies totaled six hits that tied the score or provided a lead. Five of those came in the final four innings, after Harper’s wake-up blast.

Severino finished six innings and allowed three runs. The batter immediately after Harper, Castellanos, blasted a solo shot to left-centerfield to tie it.

Brandon Nimmo put the Mets on top with a home run in the top of the seventh. Edwin Diaz blew a save in the bottom of the eighth, giving up three runs, two on Bryson Stott’s go-ahead two-run triple. Mark Vientos hit his second homer of the day in the top of the ninth, a tying two-run blast.

The teams seemed destined for extra innings until Megill, a starter pressed into bullpen duty in the postseason, crumbled with two outs in the last inning: Trea Turner walk, Harper walk, Castellanos single to end it.

At the end of a week in which the Mets staged several improbable late-game comebacks, the Phillies finally figured out a way to beat them: Take a lead when the Mets aren’t allowed to bat again.

“What an amazing game, right? Just another instant classic,” Nimmo said. “The Phillies kept coming back, putting together unbelievable at-bats, and so did we. This is what everybody wants out of October baseball. I think we put on quite a show for everybody in attendance and everybody watching on TV. It’s really fun to play baseball like this. That was, again, just an instant classic game.”

Turner said: “That’s what we expect with [the Mets]. They’re a good team. And they’ve shown already in the postseason that they’re going to battle back. There’s no quit in there and there’s no quit in our dugout as well. Good game. Glad we came out on top.”

Megill was in at the end for a few reasons. Among them: Manager Carlos Mendoza was low on high-leverage relievers, with Phil Maton and Ryne Stanek seemingly unavailable and Jose Butto already having pitched.

Mendoza called on Diaz with seven outs remaining but did not intend for him to pitch the full final 2 1/3 innings. His hope was for the closer to escape Butto’s jam in the seventh — which he did, striking out Kyle Schwarber — and get through the eighth, which he did not.

The Mets have leaned on Diaz heavily lately. He entered having thrown 105 pitches across three appearances in the previous week. He also had had the previous two days off.

“I’ve been feeling fine,” he said. “I’ve been able to work. This is a big moment for us. I gotta be ready always.”

Mendoza said: “Look, they’re a good team, they’re great hitters. It just didn’t happen today.”

Afterward, the Mets got to go home for the first time in two weeks. A road trip that bridged the regular season and postseason — Atlanta, Milwaukee, Atlanta again, Milwaukee again, Philadelphia — is over. “We’ve been on the road for the last six months, I feel like,” Severino said.

Nimmo said: “I am absolutely drained right now. You go through an emotional roller coaster and just mentally and emotionally being into every pitch and every pitch mattering so much — it does mentally drain you. But you’re so into it that you don’t realize it till you come down.”