WASHINGTON — The Mets clubhouse is home to a jumble of colorful personalities, the kinds that often have sprung from the imagination of wrestling promoter Vince McMahon.

At his indestructible peak, Matt Harvey crafted an image of himself as Batman, even using his personalized logo to sign his own name. When he’s not hitting tape-measure home runs, Yoenis Cespedes rides horses and collects Lamborghinis.

Noah Syndergaard has walked the streets of New York dressed as a Norse god, long blond locks included. Jacob deGrom has his own flowing hair that makes him look like a walking ad for conditioner.

Perhaps this is why Steven Matz has lingered under the radar, a clean-cut, plain-spoken lefthander who at first glance looks more insurance salesman than superhero.

“He’s going to get plenty of publicity,” Terry Collins said Wednesday after watching Matz toss eight shutout innings in a 2-0 win over the Nationals. “Don’t be fooled by that. He’s making a name for himself in this league and it’s going to get around here fast.”

Matz may not be “The Dark Knight” or “Thor” or “La Potencia.” But Steve from The Island has pitched like a candidate for the NL Rookie of the Year award. Consider his conquest of the Nationals, which cemented a much-needed series victory when things aren’t exactly sailing smoothly for the Mets.

When asked about his confidence, Matz said, “It’s pretty high. I just feel really comfortable on the mound.”

Jeurys Familia recorded his 16th save in as many chances, tying Francisco Rodriguez for the second-longest stretch to begin a season in Mets history. David Wright hom ered for the second time in the series, and the Mets jumped on a Daniel Murphy error to score an insurance run.

During this series, the Mets placed Lucas Duda on the disabled list and wrestled with demoting Harvey, the onetime ace who has devolved into one of the worst pitchers in baseball. Yet the Mets avenged a series loss at Citi Field last week by taking two of three. They could thank Matz for delivering the clincher.

Said Wright: “That’s as dominant a performance as I’ve seen this year.”

Matz (7-1, 2.36 ERA) is the first Met to win seven straight starts since Steve Trachsel in 2006. During the stretch, his ERA is 1.13.

One night before, Harvey made these Nationals look like the ’27 Yankees. But Matz made sure their bats went silent. At one point he retired 16 straight, then stepped up when the Nationals saw a glimmer of hope in the eighth.

Clint Robinson laced a two-out, pinch-hit single. With that, Dusty Baker summoned Bryce Harper, the feared but slumping slugger who was given a day off to clear his head. Lefty slayer Jerry Blevins was ready to enter the game, but Collins let him watch from the bullpen.

The time had come for a test.

“I think when you have a young player, there’s certain situations where you’ve got to challenge them,” Collins said. “And that was one of them for me.”

Matz fell behind 2-and-0, and as Collins watched, he heard pitching coach Dan Warthen state the obvious: “We’re going to find out what he’s made of right here.”

The answer came on Matz’s 104th and final pitch, a weak grounder to shortstop by Harper that ended the inning. Soon, Matz officially improved to 11-1 in his 14 regular-season starts in the major leagues.

When asked if he thought his confrontation with Harper was a test, Matz offered a typically understated response.

“Not really, no,’’ he said. “I’m just really in the moment, just kind of worrying about the task at hand.”