MIAMI — The torpedo doors remained shut, but Pete Alonso had little trouble sinking the enemy fleet Monday night. 

Alonso, who before the game told The Post he doesn’t use the innovative torpedo bat that has become the buzz of MLB following the Yankees homer barrage over the weekend — but will “probably order some and try them out” — got the Mets resembling a destructive force for the first time this season. 

Alonso’s grand slam was one of four homers hit by the Mets in a 10-4 demolition of the Marlins at loanDepot park. 

After three frustrating offensive games in Houston, where they managed only five runs total and lost twice, the Mets jumped all over right-hander Cal Quantrill in the fifth inning and coasted. 

The Mets first baseman was asked if there is a special feeling to hitting his first homer in a season. 

Pete Alonso of the Mets runs the bases on his grand slam against the Miami Marlins in the fifth inning at loanDepot park on March 31, 2025 in Miami, Florida. Getty Images

“It’s a long time without hitting one and to finally do it in a big league game, it feels pretty cool,” Alonso said. “I can do it still.” 

Starling Marte, Luis Torrens and Brandon Nimmo also went deep for the Mets, whose only homer over the first three games was Juan Soto’s blast on Friday. 

“We just had great team at-bats the entire game,” Alonso said. “You can’t have that big ending without team quality at-bats, and we did that throughout the entire game.” 

All of it provided plenty of support for David Peterson, who allowed two earned runs on five hits with nine strikeouts and three walks over six innings.

The lefty became the first Mets starting pitcher of the season to finish six innings. 

Among the few not involved in the outburst was Francisco Lindor — he was given a night off after returning from Orlando, Fla., where his wife Katia gave birth Sunday to the couple’s third child (and first son). 

Mets’ Starling Marte is congratulated by teammates in the dugout after hitting a home run during the third inning of a baseball game against the Miami Marlins, Monday, March 31, 2025. AP

Peterson struck out three batters in the first inning but allowed a solo homer to Otto Lopez that put the Mets in a 1-0 hole. 

Marte, batting leadoff in Lindor’s absence, homered in the third to tie it 1-1.

Marte fell behind by taking a curveball for a strike before jumping on the next pitch — a hanging curve — and clearing the left field fence. 

• CHECK OUT THE LATEST MLB STANDINGS AND METS STATS

The Mets turned the game into a runaway in the fifth, with Alonso’s fourth career grand slam as the catalyst.

Jose Siri stroked an RBI double to give the Mets a 2-1 lead and after Marte was hit by a pitch and Soto walked, Alonso worked the count full, before fouling off two sinkers.

On the third straight sinker from Quantrill, he cleared the right field fence. 

Mets pitcher David Peterson throws during the first inning of a baseball game against the Miami Marlins, Monday, March 31, 2025 AP

“[Alonso] earned that pitch,” manager Carlos Mendoza said. “He ended up hitting that grand slam. He laid off a slider, that first pitch, they were trying to make him chase. Then they painted a fastball at the knees, trying to get a ground ball there. Finally, he got a pitch he could do some damage and got the big one.” 

There was further thunder in the inning: Torrens hit a two-run homer that extended the lead to 8-1.

Mark Vientos drew a one-out walk before Torrens hit a shot to center that hit Liam Hicks’ glove at the top of the fence and bounced over. 

“[Hicks] helped that one a little bit, but that is part of the game,” Torrens said. 

In the sixth, Alonso walked before Nimmo jumped on a 1-2 slider from George Soriano for the Mets’ fourth homer of the night, extending the lead to 10-1. 

“We know we have a good offense, but there are going to be times we go through some tough stretches, that it’s going to be hard — that was the case with Houston,” Mendoza said, noting the Mets are scheduled to face Miami ace Sandy Alcántara on Tuesday. 

Peterson allowed a homer to Eric Wagaman in the sixth that gave the Marlins their final run against him. 

Huascar Brazobán and Danny Young combined to work the final three innings.

Young surrendered two runs in the ninth, snapping a streak of 12 1/3 scoreless innings by Mets relievers to begin the season.