For the first time in nearly two months, the Mets have won three straight games. 

They didn’t make it easy, but with the depleted Nationals serving as a trampoline for the home team’s recent free fall, the Mets took both ends of a doubleheader Thursday to complete a three-game sweep at Citi Field, springing them into a crucial 13-game stretch against the Dodgers and Giants. 

After Brandon Nimmo and Marcus Stroman led the way to a 4-1 win in Game 1, the Mets blew a three-run lead in the final inning of Game 2 before Pete Alonso crushed a walk-off home run for the 5-4 win. 

“This series was a huge statement, but I think we have exactly what it takes,” Alonso said. “We have so much talent, but I’ve been saying this all year long: The amount of character we have in that clubhouse, the amount of fight, resiliency and grit, I think it’s unparalleled. We have a special group and we’re willing to go full-throttle.” 

The Mets looked to be on their way to a 4-1 win in Game 2 before Trevor May and Jeurys Familia combined to blow the save in the seventh inning, after Edwin Diaz had closed out the opener. May threw 28 pitches, recording just one out and loading the bases before Familia entered and got the second out. But after a wild pitch brought one run in, the next two came around to score on Andrew Stevenson’s ground ball that got under the glove of Jeff McNeil in shallow right field, tying the game at 4-4. 

Alonso saved the day in the bottom of the inning, though, taking Kyle Finnegan deep for his 25th homer of the season. 

Before Thursday, the Mets (59-55) had not won back-to-back games since July 21-23 or three straight games since June 14-16 — at which point they had a season-high five-game lead atop the NL East. 

The road ahead will only get tougher for the Mets, with Friday’s game against the Dodgers marking the first of 13 straight against the top two teams in the NL West. But coming off a four-game losing streak, the Mets took advantage of the torn-down Nationals (50-65) to move within a half-game of the Phillies for first place in the NL East. 

“What I still want to see is for us to be hot now for a good period of time,” manager Luis Rojas said. “Everything that we did in this series — blend the pitching, good defense and catch up to the fastball and have some quality at-bats put together so we can score some runs — that’s what we need to bring over to the next series.” 

Nimmo drove in all four runs in Game 1, ripping a three-run homer and later adding an RBI single, to give Stroman a lead to work with. 

Stroman held up his end with a strong start, taking a one-hit shutout into the sixth inning before settling for 5 1/3 innings of one-run baseball. The heat proved to be a more formidable opponent than the Nationals lineup for most of the day — Stroman was tended to in the fourth inning after feeling light-headed and dizzy — but after he got into trouble in the sixth, Aaron Loup helped him get out of it with the lead still intact. 

In Game 2, Trevor Williams delivered a solid start in his Mets debut after coming with Javier Baez from the Cubs at the trade deadline. Williams, who had been optioned to Triple-A Syracuse for two starts before being called up as the 27th man Thursday, gave up just one run over 4 1/3 innings. 

Michael Conforto and J.D. Davis hit back-to-back doubles in the fourth inning and both came around to score before Jonathan Villar drilled a two-run homer in the sixth inning for insurance runs that turned out to be critical. 

“Sweeping doubleheaders is extremely difficult to do,” Alonso said after the Mets’ third sweep in 12 doubleheaders this season. “For us to be able to come through on top in both games during a long day … this is huge for us moving forward and we’re really looking forward to this weekend.”