The Mets were without Francisco Lindor once again Tuesday night and once again, they managed to beat the Nationals to inch closer to a playoff berth.

An offense that has been missing its leadoff hitter looked just fine, as they used a four-run third inning to take control of a 10-1 win at Citi Field.

Pete Alonso led the way with a three-run homer and five RBIs and Lindor’s replacement, Luisangel Acuna, delivered his first MLB homer and had three hits.

They also got another assist from the Reds, who came back to beat the Braves to help put the Mets two games ahead in the race for the final NL wild card.

When the score popped up on the scoreboard, the Citi Field crowd had a noticeable reaction.

“I didn’t know what it was,” Alonso said. “I thought it was someone just getting rowdy or chugging beers. We definitely found out.”

The Mets will go for a sweep of Washington on Wednesday in Queens before the path to the postseason gets more difficult once again, with the Phillies coming to town on Thursday for a four-game set with 11 games left in the regular season.

“We control our own destiny,” Alonso said. “That’s what we want to do: win as many ball games as we can.”

And it wasn’t just Alonso and the offense that led the way Tuesday, as Tylor Megill delivered his second straight superb outing.

The right-hander allowed just an unearned run in six innings of work.

The lineup, which had scored just three runs in the previous two games, came alive in the third against lefty Mitchell Parker.

Coming off one of his best starts of the season in Toronto, Megill delivered again.

He pitched around a two-out double by Dylan Crews in the second, whiffing Joey Gallo to end the inning.

Megill walked Jacob Young to open the second. CJ Abrams followed with a grounder to third and Mark Vientos tried to force Young at second, but Acuna missed the ball and it got away, putting runners on the corners with no one out.

James Wood drove in the first run of the game — unearned — with a groundout and Megill walked Juan Yepez and then threw a wild pitch.

But with runners on second and third, Megill rebounded to fan Luis Garcia Jr. to keep it to one run.

Harrison Bader led off the bottom of the inning with a four-pitch walk and Acuna atoned for his miscue at short with a double to left-center.

The 109-mph rocket scored Bader from first to tie the game.

Later in the inning, Alonso followed with a flare down the right field line that stayed just fair for a two-run single to give the Mets a 3-1 lead.

A Mark Vientos sacrifice fly made it 4-1.

Francisco Alvarez belted a home run of the season to lead off the bottom of the fourth.

It was just the catcher’s ninth of the season, but third homer in his last five starts.

The Mets tacked on another run in the fifth, as Tyrone Taylor knocked in Alonso with a one-out double after Alonso opened the inning with a two-bagger.

Alonso and the Mets iced it in the sixth with the first baseman’s 33rd home run of the year, a three-run shot.

“I think all of us have risen to the occasion,” Alonso said of the team’s recent play, especially in the wake of Lindor’s injury. “Not a lot of people would have seen us in this position four or five months ago. A lot of people didn’t.”

But now it’s a playoff atmosphere in Queens, with the Mets rolling and the postseason in sight.

“We’ve got to take care of business,” Carlos Mendoza said. “We can’t worry about what’s going on outside this building. We have to continue to play well. If we do that, we’ll get where we want to get.”