The opponent changed, but the Mets just kept blasting away Thursday.

After two straight days piling on the hapless Nationals, manager Carlos Mendoza’s crew steeled for a larger challenge against the NL East leader, even with weak link Taijuan Walker on the mound for the Phillies.

Walker, after all, had fired three innings of scoreless relief last Saturday to help the Phillies beat the Mets, but on this night he served as additional batting practice.

The Mets clobbered four home runs against the right-hander and rolled to a 10-6 victory in front of 35,982 at Citi Field.

The Mets, who established a franchise record by scoring at least 10 runs in a third straight game (they scored 10 in each of the final two games of a sweep of the Nationals), won their fourth straight and for the 16th time in their last 20 games.

They remained tied with Arizona for the NL’s second wild card and kept their two-game lead on Atlanta for the third spot intact.

Mark Vientos, Pete Alonso, Brandon Nimmo and Francisco Alvarez all homered, with Francisco Lindor absent from the lineup for a fourth straight game with lower back soreness.

The Mets, who have three home games remaining, fed off a boisterous crowd.

“It felt like a playoff game and to us it is,” Nimmo said. “These games, we are trying to win every single one of them and these guys are very fired up for making this push here at the end. All the other teams [in the race] are playing well also, so that makes every game even more important.”

Luis Severino wasn’t his sharpest, but kept the Mets competitive with three earned runs allowed on five hits and two walks with seven strikeouts over six innings.

It was Severino’s second straight start against the Phillies, and in both he allowed three runs over six innings.

Vientos and Alonso hit consecutive homers in the first inning to give the Mets a 2-0 lead. It marked the sixth time this season the Mets went back-to-back with homers.

Vientos’ blast was his 25th of the season and Alonso extended his team lead with his 34th.

“Right now especially with the way we are playing and we’re coming down the home stretch, it’s just something you dream about in the offseason,” Alonso said. “Like, ‘Man, I want to be in that position.’ We all worked really hard to be in this position and to have that energy and feedback from the fans … that just helps us play better.”

After Trea Turner homered in the second to tie it 2-2, the Mets went back on the rampage in the bottom of the inning.

Jose Iglesias singled leading off and Nimmo cleared the fence in right-center.

Severino struggled through the fourth, allowing two hits and a walk to pull the Phillies within 4-3.

Brandon Marsh stroked a two-out RBI single following a walk to J.T. Realmuto.

“This team we are facing is really good, they score runs, so they are not just going to go out there and be shut out for nine innings,” Severino said.

Alvarez’s three-run rocket in the fourth was the highlight of an inning in which the Mets sent 10 batters to the plate and scored five runs.

J.D. Martinez was plunked to begin the rally and Tyrone Taylor walked before Alvarez pounced on a high sinker for his second homer in three games and fourth since Sept. 11.

But the Mets kept adding in the inning. Iglesias singled and Nimmo’s RBI double buried the Phillies in an 8-3 hole.

Vientos’ ensuing RBI single passed the baton before walks to Alonso and Jesse Winker loaded the bases. But the good times ended with Martinez grounding into an inning-ending double play.

“It’s an extremely long lineup right now and we’ve got a lot of guys swinging the bat well,” Nimmo said.

Danny Young allowed three runs in the seventh that sliced the Mets lead to 9-6.

Bryce Harper’s two-out double against Reed Garrett that brought in two runs was the inning’s big hit.

Luisangel Acuna delivered an RBI triple in the seventh that widened the lead to 10-6.

It was just the latest contribution from the rookie, who homered in each of his two previous games.

“Having the fans behind us, the atmosphere today was incredible,” manager Carlos Mendoza said. “A really good crowd and they were into it from the beginning. The fans are supporting the team, so we believe, they believe and it’s fun right now.”