NEW YORK -- Pete Alonso golfed an early three-run homer and the New York Mets hammered an ineffective Jack Flaherty, extending the National League Championship Series with a 12-6 victory over the Los Angeles Dodgers in Game 5 on Friday.

Starling Marte had three doubles, four hits and three RBIs for New York. Francisco Alvarez broke out of a slump with three hits, including an RBI single in a five-run third inning. Francisco Lindor and Jesse Winker each laced an RBI triple.

The Mets' 12 runs were one shy of matching their most in a postseason game in franchise history (13 in Game 3 of the 2015 NL Division Series against the Dodgers). They were their most in a postseason game when facing elimination.

"I think that this is about momentum, and we take the momentum back today," Alvarez told Fox after the game. "So we have to keep going with the two games in Los Angeles."

After getting blown out in three of the first four games, including the past two nights at home, the wild-card Mets saved their season for the second time in these playoffs -- both with the help of a three-run shot by Alonso. They trimmed their series deficit to 3-2 and sent the best-of-seven NLCS back to Los Angeles for Game 6 on Sunday.

Sean Manaea is expected to start for New York on five days' rest, while the Dodgers are likely to go with another bullpen game because of a thin rotation decimated by injuries.

"We come from a lot of adversity," Díaz said. "We can beat them."

With an opportunity to pitch his hometown team into the World Series, Flaherty flopped. After throwing seven shutout innings of two-hit ball in a Game 1 win, he fell behind 3-0 four batters in when Alonso launched a low slider 432 feet to center field for his fourth homer this postseason.

Alonso, poised to become a prized free agent this fall, also connected on a go-ahead shot with the Mets facing elimination in Game 3 of their Wild Card Series in Milwaukee. That one was more dramatic, coming with New York trailing 2-0 and down to its final two outs in the ninth.

But again, Alonso went deep to help extend his tenure in a Mets uniform.

"Honestly, I was just looking for something over the middle of the plate," Alonso said. "I mean, I didn't really realize how low the pitch was. I got caught a little out front. But location-wise, it was low, but it was still over the middle of the plate. And I'm just really happy I could come through right there for the fellas. I'm just so happy because this group is so special. And I'm happy that we get to live to fight another day and play another game of baseball together."

Flaherty allowed eight runs and eight hits in three innings. He failed to strike out a batter for the first time since a September 2022 game with St. Louis against Pittsburgh.

After striking out 12 times Thursday night, the Mets did not strike out once in Game 5. That's the first time that has happened in the postseason since Game 2 of the 2002 World Series, when the Los Angeles Angels didn't strike out against the San Francisco Giants. The Mets joined the New York Yankees and Pittsburgh Pirates (both in Game 7 of 1960 World Series) as the only teams not to strike out in elimination games.

"We came in with the same mentality: Go and win this game and go back to L.A.," Diaz told Fox after the game. "We played really good baseball against a really good team. At the end of the day, the guys did their job and the bullpen did their job. And we got the W."

Handed an 8-1 lead, New York starter David Peterson was unable to make it through the fourth.

Dodgers rookie Andy Pages homered twice and drove in four runs. Mookie Betts went deep for the second consecutive game, helping Los Angeles cut an eight-run deficit to 10-6.

But then relievers Ryne Stanek and Edwin Díaz settled things down, and the Mets put this one away. Stanek worked a career-high 2 innings for the victory, and Díaz got six outs without permitting a run.

Information from ESPN Research and The Associated Press was used in this report.