NEW YORK — Noah Syndergaard knows he needs to speed up.

Not his fastball; he throws harder than most anyone. His delivery, that’s what’s still way too slow.

Bryce Harper hit two doubles and became the latest player to swipe a base against Syndergaard as the Washington Nationals beat the New York Mets 4-1 Friday night.

Washington won its fourth in a row and leads the NL East by 10 1/2 games over the wild card-contending Mets. Like a lot of teams, the Nationals came out running on Syndergaard, stealing four bases in the early innings.

“In the next five days, going to work on getting quicker again,” he said.

Tall and slow to the plate, Syndergaard has had 45 runners steal with him on the mound — the most against any pitcher since Hideo Nomo in 2001, ESPN Stats & Info said. Only six runners have been caught with Syndergaard pitching.

Trea Turner led off the game with a single, stole two bases and scored on Harper’s sacrifice fly.

“Yeah, he’s real fast, very aggressive, and Noah’s going to have trouble with those kind of guys,” Mets manager Terry Collins said.

Harper doubled with one out in the fourth, stole his 19th base with two outs and came home on a single by Wilson Ramos.

“It’s all around the league that he doesn’t hold runners yet,” Nationals manager Dusty Baker said.

Baker said the strategy does more than set up runs. It also seems to rankle Syndergaard.

“He’s prideful,” Baker said. After a steal, he added, “he looks at the runner and doesn’t like it very much.”

Syndergaard (12-8) gave up just three hits in seven innings and retired his final 10 batters.

Along with shutting down the Nationals in the middle innings, Syndergaard might have shut down the crowd, too. Earlier this week, he wrote on Twitter and said on video that he wasn’t a fan of fans doing the wave.

Harper’s double set up Anthony Rendon’s two-run single in the ninth.

Daniel Murphy singled in the ninth, and has a hit in all 14 games against the Mets this season. He also stole a base against the team he boosted to the World Series last year.

A.J. Cole (1-1) earned his first major league win, giving up one run and three hits in six innings. He struck out five in his fourth career start.

Asdrubal Cabrera homered for the sixth time in eight games, sending a drive over the right-center wall in the Mets fourth. His 19th home run came one pitch after he hit a long fly that barely hooked foul into the upper deck in right field.

Mark Rzepczynski, Koda Glover, Oliver Perez and Mark Melancon combined for three innings of scoreless relief. Melancon closed for his 38th save.

CABRERA’S POWER

Of Cabrera’s 19 home runs, 18 have come as a shortstop. That’s one behind the club record for the position set by current teammate Jose Reyes in 2006.

COVER CHARGE

Reyes struck out twice in going 0 for 4, but he still managed to knock the cover off the ball. Literally, he did. In the first inning, Reyes hit a foul that kept spinning quickly in the batter’s box, with a flap of the ball coming loose. Reyes and Ramos watched it spin into the dirt for several seconds.

TRAINER’S ROOM

Nationals: RHP Stephen Strasburg (sore elbow) threw a bullpen and was feeling good, Baker said. There was no timetable for his return to the rotation, but Baker figured “probably pretty soon.”

Mets: Collins said LHP Steven Matz (shoulder tightness) will head to the team’s spring training complex in Florida after this weekend and start throwing again Monday. Matz is on the disabled list and hasn’t pitched since Aug. 14.

UP NEXT

Nationals: RHP Tanner Roark (14-7, 2.87 ERA) is 3-0 with a 1.82 ERA at Citi Field in seven games, four of them starts.

Mets: RHP Robert Gsellman (1-1, 3.72) makes his second major league start. Among those in attendance will be Laurie Hernandez, who won a gold medal with the U.S. Olympic women’s gymnastics team and will throw out the first ball.