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 a best-of-five division series against the NL East champion Phillies on Saturday in Philadelphia.

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

New York went 6-7 against the Phillies in the regular season and finished six games behind them in the division standings.

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 NL Championship Series in 2018.

This series loss will be particularly painful.

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.

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 on Alonso, who hit 226 homers in six seasons but hadn't gone deep since Sept. 19.

After taking a 3-1 lead, Alonso sent a 3-1 exchange 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.

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.

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 one and two innings of scoreless relief to secure the victory. 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.