On a brisk day in Washington, D.C., the Mets erased a pair of one-run deficits to rally past the Nationals 3-2 behind a beautiful rebound by starter Steven Matz — making amends for his subpar season debut.

“The main thing is trust what I have out there and go out and attack them,” Matz said. “Don’t try to pitch around contact. Just go right after them. That was my mentality the whole game and that’s the way I have to be.”

The Long Island lefty pitched five innings of one run ball (unearned) and scattered three hits along with seven strikeouts and a couple of free passes. However, like Matt Harvey before him, he didn’t stay long enough at the fair to garner the win.

However, for Matz, it was a step in the right direction and a start to build off going forward.

“It was a minor adjustment of something I was doing in spring training as well early on, not having that last bit of conviction with my pitch, mentally and physically,” Matz said. “Just finishing, really.”

Eight games in, rookie manager Mickey Callaway’s crew is working on all cylinders with timely hitting, highlight reel defense, and a bullpen that continues to baffle opposing batters.

Callaway seconded Matz’s notion about pitching with more conviction.

“There was a lot more confidence,” he said. “Total conviction in most of his pitches. You could see it in the way he released the ball. So he did a great job, making that adjustment.”

In the top of the second, center fielder Juan Lagares’ grab and release rocket gunned down Brian Goodwin at the plate, trying to score on a single by Pedro Severino.

“He’s awesome out there,” Matz said. “It was huge; in a tight game he comes up firing like that.”

Former Yankee Todd Frazier redeemed himself in the sixth drilling a double off the right field wall, an inning after sailing a routine ground ball past Wilmer Flores for the Nats first go-ahead run.

“I got a good run back and felt better about the game after that,” Frazier said.

Travis d’Arnaud followed up with a game-tying RBI base hit up the middle and prodigal son, Jay Bruce, 2-for-4 on the day, knocked starter Gio Gonzalez off the rubber with a single to right.

Washington wunderkind Bryce Harper took Mets reliever Hansel Robles deep on a fastball off the plate, a good pitch that the hot-hitting right fielder contorted his body for a 2-1 lead.

The Mets got even in their next at bat after Amed Rosario led off with a single, then flew around the bases on Asdrubal Cabrera’s rip roaring double to deep right.

Cabrera took third on Yoenis Cespedes’ ground out to short, Michael Conforto was given a pinch-hit intentional walk, and Cabrera scored on Frazier’s sharp ground out to second that Howie Kendrick bobbled for New York’s go-ahead, eventual winning run.

“It can be contagious,” Callaway said. “There’s something to be said when you give up a run and your guys come in and are raring to go and score another one.”

Rookie reliever Jacob Rhame entered the eighth and erased former Met Matt Reynolds, the only batter he faced, giving way to veteran Jerry Blevins who gave up a one out walk to Harper. And closer Jeurys Familia, repeatedly blowing into this cold right hand, recorded five outs for his fourth save.

“The players, they’re just doing the job,” Callaway said. “It’s almost like you throw anybody in any situation [and] they’re going to get the job done.”

Today, Harvey returns to the mound after his strong comeback debut, as the Mets try to sweep their division rivals before a three-game series in Miami against the struggling Marlins.