BALTIMORE — Through the thick Maryland humidity, signs of life emerged Wednesday from a Mets team that desperately needs a hot streak.

Among the successes for the Mets in their 9-4 victory over the Orioles at Camden Yards to snap a five-game skid was David Peterson’s seamless adaption to a different role.

Moved to the bullpen as a long reliever — at least for this day — the rookie left-hander pitched four scoreless innings behind shaky Michael Wacha, boosting a bullpen that had been on fumes recently.

Michael Conforto led the offensive charge with a 4-for-5, five-RBI performance on a day the Mets totaled 14 hits. Most of the Mets’ damage came in the seventh and eighth innings, after Peterson had stifled the opposition.

“The message I gave in summer camp when you guys asked me was I was ready to contribute at any level and at any position the team is asking me for,” Peterson said. “That is the mindset I took in today.”

Peterson, who is 3-1 with a 3.03 ERA in six appearances this season, last pitched in Friday’s doubleheader at Yankee Stadium. He had previously been sidelined with left shoulder inflammation. In his four innings of work against the Orioles he allowed two hits and two walks, throwing 59 pitches.

Manager Luis Rojas indicated Peterson might return to starting the next time through the rotation. He says he selected Wacha over Peterson for this game because of the right-handed bats stacked in the middle of the Orioles lineup and wanting Wacha to face them. The Mets considered such a hybrid plan for the rotation in spring training, when Wacha and Steven Matz were competing for one starting spot.

“[Peterson] has been very good for us — he just goes out there and gets the job done,” Wacha said. “I have been very impressed with his stuff and the way he carries himself around the clubhouse. Going into the game with a pitch count, I kind of figured he would be piggybacking me.”

Wacha was removed after just three innings in which he threw 69 pitches, allowing two earned runs on four hits with a walk. Peterson had started warming up in the second inning as the Orioles were scoring twice to tie the game.

Wacha clipped Cedric Mullins with a pitch to force in the second run of the inning. The trouble had started with Pedro Severino’s leadoff triple, on which Jake Marisnick hit the center field fence full-throttle but remained in the game. Ryan Mountcastle’s RBI single pulled the Orioles within 2-1. Wacha recorded a second out before Pat Valaika singled and Andrew Velazquez walked to load the bases.

“If Wacha would have thrown six innings, I don’t think we would have seen David Peterson in there,” Rojas said. “But David coming in and giving us the length we needed put us in a position to win the ballgame as well.”

The Mets smashed two homers as part of their onslaught. Conforto launched a two-run blast to the opposite field in the first inning, and Pete Alonso hit a solo rocket in the sixth that ended left-hander John Means’ day. Alonso’s homer was the fifth in the history of the ballpark to reach the second deck in left field.

In the seventh Conforto doubled for his fourth RBI of the game. Jake Marisnick delivered an RBI single in the eighth before Jeff McNeil’s double brought in another run, ahead of a passed ball that extended the Mets’ lead to 8-2. Conforto then delivered an RBI single for his fifth RBI.

Conforto’s RBI double in the fifth just missed clearing the fence in left-center for his second homer of the game, but was good enough to give the Mets a 3-2 lead after Amed Rosario had walked to begin the inning. The walk was Rosario’s second of the week after going 101 plate appearances to begin the season without one.

Conforto’s homer in the first came after J.D. Davis singled in the inning. Davis had returned to the lineup after missing the previous two starts with left hip discomfort. Davis was the DH on this day, with new arrival Todd Frazier at third base.