WASHINGTON — Noah Syndergaard had far too much time to dwell on allowing 10 runs in his last start. One thought, in particular, continued to surface.

“I wanted to make sure that never happened again,” the Mets right-hander said.

There was never a hint it would on Monday as Syndergaard pitched seven shutout innings and struck out 10 while the Mets defeated the Washington Nationals, 7-3.

Jeff McNeil hit a two-run homer for the Mets, who were playing a holiday afternoon game about 15 hours after falling to the Phillies in Philadelphia on Sunday night. The Mets remained four games behind the Chicago Cubs for the National League’s second wild-card spot.

The Nationals loss ended their four-game winning streak and prevented them from moving 20 games over .500 for the first time this season.