Pete Alonso launched a tiebreaking homer and Jacob deGrom pitched well enough to help save the New York Mets’ season with a 7-3 victory over the San Diego Padres that evened their wild-card playoff series at one game apiece Saturday night.

Francisco Lindor also went deep, Jeff McNeil laced a critical two-run double and All-Star closer Edwin Díaz entered much earlier than usual to protect a one-run lead in the seventh inning.

New York broke open the game by scoring four times in the bottom half, keyed by the bases-loaded double McNeil lined off Adrian Morejon through a drawn-in infield.

Seth Lugo retired cleanup hitter Josh Bell on a bases-loaded grounder for the save, ending a game that took 4 hours, 13 minutes.

“Win or go home,” deGrom said. “Love pitching here. Mets fans have been great to me. Didn’t want to disappoint.”

The teams play a decisive Game 3 on Sunday night at Citi Field, with the winner advancing to a best-of-five NL Division Series against the top-seeded Los Angeles Dodgers beginning Tuesday.

Joe Musgrove is scheduled to start for his hometown Padres against 15-game winner Chris Bassitt.

“We feel good,” San Diego manager Bob Melvin said.

Leadoff batter Brandon Nimmo had three hits and a walk for the Mets, including a go-ahead single in the fourth that chased wild starter Blake Snell to the delight of a boisterous sellout crowd waving orange rally towels.

The left-hander walked four of his first 12 batters and six in all over 3 1/3 shaky innings in his first postseason start for San Diego.

In a matchup between the 2018 Cy Young Award winners, deGrom struck out eight in six innings of two-run ball for his fourth career postseason win.

“He kept us off balance,” Melvin said. “It was a close game in the middle innings and then it got away from us there in the seventh.”

It was deGrom’s first playoff start at home — the right-hander helped pitch the Mets into the 2015 World Series, but all four of his starts that postseason came on the road.

One night after co-ace Max Scherzer gave up four homers and seven runs in a Game 1 flop, deGrom delivered with New York on the brink of elimination.

The two-time Cy Young Award winner, who has said he plans to opt out of his contract after this season, whiffed Manny Machado all three times and rebounded nicely after going 0-3 with a 6.00 ERA in his final four regular-season outings.

“I actually felt like I had my best stuff in the sixth inning,” deGrom said.

Trent Grisham homered for the second time in two games, and San Diego tied it 2-all on Jurickson Profar’s RBI single in the fifth.

But after a visit from pitching coach Jeremy Hefner, deGrom struck out Machado and Bell with runners at the corners to end the inning.

Alonso homered on the first pitch in the bottom half from reliever Nick Martinez, who went to college in New York City at Fordham. It was the first career postseason homer for Alonso, who had 40 during the regular season and tied for the major league lead with 131 RBIs.

Díaz was summoned by manager Buck Showalter in the seventh — his earliest appearance in a game since August 2020. The reliever made a tough defensive play covering first base and then retired slugger Juan Soto with a runner on second to end the inning.

Díaz went 46 minutes between pitches while the Mets rallied in the bottom half with the help of consecutive 10-pitch walks drawn by Alonso and Mark Canha against Morejon.

A pumped-up McNeil, the big league batting champion, pointed toward the New York dugout as he legged out his clutch double that made it 5-2. Eduardo Escobar added an RBI single off Pierce Johnson, and pinch-hitter Daniel Vogelbach had a sacrifice fly.

After getting two outs in the eighth, Díaz was lifted to a warm ovation and waved to the crowd of 42,156 as he walked off the mound.

With two on in the ninth, Profar nearly made it close on a long drive caught just in front of the fence. Adam Ottavino walked in a run before Showalter went to Lugo for the final out.

TRAINER’S ROOM

Mets: RHP Taijuan Walker replaced left-handed reliever Joely Rodríguez (shoulder) on the series roster before the game, an injury substitution that needed to be approved by Major League Baseball. Rodríguez won’t be eligible to return unless the Mets reach the NL Championship Series. He did not pitch in Friday night’s 7-1 loss. ... Slumping DH Darin Ruf returned from a neck strain and played his first game since Sept. 25. Showalter picked the 36-year-old Ruf, an eight-year major league veteran, at DH over 20-year-old catcher Francisco Álvarez, rated baseball’s top prospect by MLB.com before making his major league debut Sept. 30. Ruf ended the season with four hits, none for extra bases, in his final 48 at-bats (.083). But he’s excelled against left-handed pitching throughout his career and entered 3 for 7 with a home run and three walks against Snell. “A little history there. I like the flexibility it gives us with the catchers,” Showalter explained. “Darin’s got a little bit more of a track record, especially where the Padres are concerned.” Ruf struck out, walked and was hit by a pitch. ... All-Star RF Starling Marte moved from sixth in the batting order back up to his regular No. 2 slot. Marte went 2 for 4 with two steals Friday night in his first game since Sept. 6, when he was hit by a pitch and broke the middle finger on his right (throwing) hand.

Brandon Drury started at first base for San Diego instead of Wil Myers, the only lineup change from Game 1 made by Melvin.

UP NEXT

Musgrove (10-7, 2.93 ERA) grew up a Padres fan in the San Diego suburbs and signed a $100 million, five-year contract with his hometown team this season.

Bassitt went 15-9 with a 3.42 ERA in his first season with the Mets after coming over in a trade with Oakland, where he pitched for Melvin.