J.A. Happ found a way to take the short porch out of play.

Coming off a series of disastrous starts at Yankee Stadium — including a loss last week in which the southpaw bemoaned the shallow dimensions in right field — Happ rebounded with one of his best starts in The Bronx, allowing one hit in five-plus shutout innings in the Yankees’ 3-1 win over the Mariners on Thursday night.

Happ (2-3), who struck out seven and walked three, hasn’t allowed a run in two of his past three starts.

“I think I just held some frustration from that last start,” said Happ, who surrendered two homers against the Twins. “Pitching with an edge or whatever you want to call it, I was definitely focused out there. I do think that helped a little bit.”

Entering the night, Happ was 0-3 with a 7.65 ERA at Yankee Stadium this season, having allowed 17 runs — including seven home runs — in 20 innings. But against the best home run-hitting team in the majors this season, the lefty never came close to danger.

After walking two in the first inning, Happ quickly mowed down the Mariners, carrying a no-hitter until Tom Murphy’s two-out single in the fifth. Happ, who was removed after 94 pitches and a walk to open the sixth inning, lowered his ERA to a season-best 4.36.

After failing to throw at least five innings in his first four starts of the season, Happ has thrown at least five innings in his past five starts.

“He’s been fighting hard, really grinding, even from late in spring training, early in the season, just trying to find that way,” manager Aaron Boone said. “I think he’s done a good job of making different adjustments at times. To see him go out and really throw it like he did and pound the zone was really good to see. He was pretty intense throughout that game, and he got us off on the right foot, for sure.”

Happ and Boone were most pleased with the improvement in the 36-year-old’s four-seam fastball.

“I felt like I had a little better drive on it. I feel like it was more consistent,” Happ said. “That’s something that we really focused on in between starts. I felt like that was the most consistent it’s been all season, which is a good sign for me. … I think it allows the other stuff to play better. I think that was probably the difference.”