By the time he stepped on the rubber Friday night, Mets lefthander Steven Matz already had moved long past the point of trepidation. He had been poked and prodded, subjected to a battery of tests with alphabet soup acronyms. They confirmed what he already knew. His arm was fine.

“This was all the peace of mind I needed,” Matz said after pitching the Mets to a 3-2 victory over the Brewers.

The time had come for a cleansing. The previous two days had been spent getting outscored 16-2 by the Nationals, who pounded Bartolo Colon and left Matt Harvey to pick up the shattered shards of his confidence.

The Mets (23-18) suddenly found themselves living in an upside-down world in which they had forgotten how to pitch. But Matz restored order, holding the Brewers to two runs and three hits in seven strong innings.

It had been 10 days since Matz was skipped with soreness in his left elbow and forearm. But he shrugged off a two-run homer by Chris Carter in the first and quickly rediscovered his rhythm.

“More than anything, you’re concerned about the command,” said manager Terry Collins, who watched Matz strike out eight without issuing a walk.

Michael Conforto showed signs of breaking out of his May slump, hammering a two-run homer to the opposite field in the sixth inning to give the Mets a one-run lead they would keep.

Setup man Addison Reed worked a spotless eighth inning ahead of closer Jeurys Familia, who nailed down his 14th save in as many chances this season. With that, the Mets began the process of cleansing the taste of a bitter week.

“It feels like we’re now heading in the right direction,” said Conforto, whose seventh homer came off Brewers righthander Wily Peralta.

The night belonged to Matz, who has won six straight decisions and posted a 1.35 ERA in that span. He departed after 88 pitches, with Collins making good on his vow to take it easy on the lefty in his first start coming off a layoff.

Matz’ outing came at an opportune time. The struggles of Colon and Harvey left the bullpen vulnerable, with the Mets on the brink of making a roster move to cover themselves.

“We needed it bad,” Collins said. “We were really short in the pen . . . We needed someone to go six innings. He gave us seven.”

In spring training, fellow Long Islander and former Mets lefthander Frank Viola predicted that Matz, 24, would be in contention for the National League Rookie of the Year award. To this point, Viola has proved prophetic.

Matz (6-1) is the first Met to win six straight decisions since R.A. Dickey did it from May 22 to June 18, 2012. He leads all NL rookies with his six victories and his 2.81 ERA is the lowest among all rookie starters.

In 13 big-league starts, Matz is 10-1, and he again showed that staying on the field has been his only problem.

Matz’s only mistake came in the first when he grooved a 94- mph fastball over the heart of the plate to Carter. But from there, Matz worked quickly, seizing control of the tempo of the game and retiring 15 in a row at one point.

“He likes to work fast,” catcher Rene Rivera said. “And that’s good for a pitcher, to keep the pace going and keep the batters off balance.”

Notes & quotes: David Wright was off Friday night, which should allow him to play day games Saturday and Sunday . . . Outfielder Kirk Nieuwenhuis and reliever Carlos Torres may be playing for the Brewers, but the Mets did not forget their contributions to last year’s pennant-winning team. Both were presented rings before the game . . . Familia wore an ice pack over his left knee after he was hit by a comebacker in the ninth, but he said he should remain available.