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

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

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

“That 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 in the regular season and finished six games behind them in the division standings. According to ESPN Stats & Information, the 1,081 all-time meetings between the Mets and Phillies are the most between two franchises without a playoff matchup since 1962.

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 particularly painful.

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

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

Twelve Mets had been shut out in a row when they opened Game 9 against Williams, a two-time NL reliever of the year who earned the save in Milwaukee's Game 2 victory on Wednesday.

But he wasn't himself that night.

“I’m not going to apologize,” Williams said. “I didn’t execute the way I should have. They got the job done, but I didn’t.”

Francisco Lindor opened the ninth half with a 3-2 away score. After Mark Vientos struck out, Brandon Nimmo singled to put runners on the corners.

That brought up Alonso, who has hit 226 career homers over six seasons but hasn't gone deep since Sept. 19.

“I know Devin has great stuff,” 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, Alonso sent a changeup over the right-field wall. He put his fingers to his mouth in a “chef's kiss” gesture as he rounded first, giving the Mets the lead.

Alonso is eligible to become a free agent after the World Series, so if the Mets had come up short, it could have been his last plate appearance with the only professional franchise he played for. Instead, he sent them into 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 home run while trailing in the ninth inning or later of a win-win postseason game.

“It’s something you practice in the backyard as a kid,” Alonso said.

Williams stayed in the game but never got back to his feet. Jesse Winker was hit by a pitch with two outs, stole second and scored an insurance run on Starling Marte's single to right. Winker, a former Brewer who was met with boos throughout the series, screamed and slammed his helmet to the ground after sliding across the plate.

The comeback in the ninth inning continued New York's picture-perfect season. The Mets were 22-33 at the end of May but played as well as anyone in baseball the rest of the regular season. They only secured a playoff spot when they scored all of their runs in the final two innings of an 8-7 win over Atlanta in the opening game of a doubleheader on Monday, the day after the regular season was supposed to end.

“It's just the makeup of this team to never give up, to never listen to the outside noise telling you to give up, not to 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 hit a double play to end the series.

Edwin Díaz pitched 1⅔ innings of scoreless relief and earned the win. David Peterson, making his first relief appearance this season, managed to get his first major league save in the ninth.

The game began as a pitchers' duel between Myers and New York's Jose Quintana. Myers pitched five shutout innings while Quintana held the Brewers scoreless for six innings.

Information from The Associated Press was used in this report.