MILWAUKEE – Pete Alonso hit a go-ahead, three-run homer off closer Devin Williams in the ninth inning, and the New York Mets defeated the Milwaukee Brewers 4-2 on Thursday night to win their NL Wild Card Series.

With their latest thrilling comeback in the decisive Game 3 against Milwaukee, the Mets advanced to the playoffs for the first time since winning the 2015 National League pennant. They advance to a best-of-five division series starting Saturday in Philadelphia against the NL East champion Phillies.

It will be the first postseason meeting between the old rivals.

“This was unreal. What a ride,” said Alonso. “I’m just excited to help keep this team alive.”

New York went 6-7 against the Phillies during the regular season, finishing six games behind them in the standings. The 1,081 all-time meetings between the Mets and Phillies are the most between two franchises without a playoff match since 1962, according to ESPN Research.

The Brewers, making their sixth playoff appearance in the last seven years, still haven’t won a postseason series since reaching Game 7 of the National League Championship Series in 2018.

This series loss will be extremely painful.

“I love this team,” manager Pat Murphy said. “I love them. I will never be able to duplicate 2024. It didn’t end the way we wanted. It ended tragically, actually.”

Milwaukee appeared to have the victory in hand after Jake Bauers and Sal Frelick broke a scoreless tie by opening the seventh inning with back-to-back homeruns off José Buttó. Tobias Myers and three relievers had combined for a two-hit shutout through the first eight innings.

Twelve straight Mets had been shut out when they opened the ninth against Williams, a two-time NL reliever of the year who had earned the save Wednesday in Milwaukee’s Game 2 victory.

But he wasn’t his normal self this evening.

“I’m not going to make any excuses,” Williams said. “I didn’t execute the way I was supposed to. They got the job done and I didn’t.”

Francisco Lindor led off the ninth with a walk on a 3-2 pitch outside. After Mark Vientos struckout, Brandon Nimmo singled to put runners on the corners.

That brought up Alonso, who has 226 home runs in six seasons but hasn’t gone deep since Sept. 19.

“I know Devin has great things,” Alonso said. “I’ve seen him throw a lot. We were teammates in the WBC (World Baseball Classic). He’s a tough AB.”

After taking a 3-1 lead in the count, Alonso sent a changeup over the wall in right field. He brought his fingers to his mouth in a “chief’s kiss” as he went around first and gave the Mets the lead.

Alonso can become a free agent after the World Series, so it could have been his final plate appearance with the only professional franchise he has played for had the Mets fallen short. Instead, he sent them through to the next round with the biggest home run of his career.

According to ESPN Research, the slugger became the first Major League player to hit a go-ahead homer while trailing in the ninth inning or later of a winner-take-all postseason game.

“This is something you practice in the backyard as a kid,” Alonso said.

Williams stayed in the game, but never regained his place. Jesse Winker was hit by a pitch with two outs, stole second base and scored an insurance run on Starling Marte’s single to right. Winker, a former brewer who was met with boos during the series, screamed and hit his helmet on the ground after sliding across the plate.

The ninth-inning comeback continued New York’s storybook season. The Mets were 22-33 at the end of May, but played as well as anyone in baseball for the remainder of the regular season. They only clinched a playoff berth when they scored all their runs in the final two innings of an 8-7 victory over Atlanta in the opening game of a doubleheader Monday, the day after the regular season was supposed to end.

“It’s just the makeup of this team: never give up, never listen to the outside noise telling you to give up, to not even try. It’s over,” Nimmo said. “Just keep going. Just keep going. And these guys embody that.”

Frelick led off the bottom of the ninth with a single, but Joey Ortiz struck out and Brice Turang grounded into a double play to end the series.

Edwin Díaz pitched 1⅔ innings of scoreless relief to get the win. David Peterson, making his first relief appearance of the season, worked the ninth to get his first Major League save.

The game started as a pitching duel between Myers and New York’s Jose Quintana. Myers pitched five shutout innings, while Quintana held the Brewers scoreless through six.

This report used information from The Associated Press.