PITTSBURGH — Jon Niese studied harder and made better pitches, but maybe the best cure yesterday for his recent slump was facing the Pirates.
You know, the team with the .217 batting average that plays in the scenic but mostly empty ballpark. Niese’s truer tests are still to come, but the lefty at least got the Mets a victory on yet another day they scuffled for runs.
“I just wanted to concentrate on fixing what I needed to fix,” Niese said after the Mets’ 3-1 victory at PNC Park that completed a .500 road trip.
Niese, who allowed one run over 7 2/3 innings yesterday, surrendered eight runs and four homers in a debacle Friday at Toronto that rated as his worst career performance. It prompted pitching coach Dan Warthen to tell Niese he needed to work harder on studying opponents he seldom faces.
The Pirates fell into that category. Niese, who hadn’t won since his second start of the season, watched more video than usual and ultimately got the desired result, even as he mostly refrained from throwing his signature curveball. Niese used the pitch barely a half dozen times, relying instead on his cutter and fastball.
“We all feel Jon has great stuff, and sometimes he trusts his stuff more than realizing he has to pitch,” Warthen said. “And today I thought he pitched, as well as using his good stuff.”
Against NL East hitters, Niese has a mental picture of what he’s trying to accomplish, according to Warthen, because of familiarity. Warthen wants Niese to have that same mental picture facing teams outside the division.
“Look at the video, see the video, but see the swing,” Warthen said. “Without even having a game report you should have an idea how to pitch a guy.”
The Mets (24-20) finished with two victories in three games against the Pirates and tonight open an 11-game homestand during which they face the Padres, Phillies and Cardinals.
As Terry Collins awaits the emergence of a slumping lineup, he will certainly take the pitching he has received since Niese’s dud in Toronto. Over the last five games of the trip, the Mets surrendered an average of three runs.
“If you pitch, you can scratch some runs out,” Collins said. “But if you’re not pitching and you’re not hitting, that’s a bad combo.”
Niese (3-2, 4.29 ERA) took a shutout into the sixth, when Andrew McCutchen stroked an RBI single to pull the Pirates within 3-1. But Niese got Neil Walker to hit into an inning-ending double play before the Pirates could get closer. Overall, Niese allowed five hits and two walks with five strikeouts.
“I did a lot more preparation this go-around, but I still had to trust my stuff and still had to have confidence in it,” Niese said. “I didn’t want to go away from my strengths. Make them adjust to me instead of me adjust to them.”
David Wright delivered an RBI double against Charlie Morton (2-5) in the fifth, extending the Mets’ lead to 3-0. Wright finished 1-for-4 and saw his average dip to .399 — the first time it has been beneath .400 since May 13.
Kirk Nieuwenhuis’ sacrifice fly in the fifth had given the Mets a 2-0 lead after Mike Baxter’s single put runners on the corners with one out. Baxter started at leadoff in slumping Andres Torres’ place for the second straight day and figures to see more action in the starting lineup during the upcoming homestand. Lucas Duda’s RBI single in the first got the Mets started.
Niese, with help from Bobby Parnell and Frank Francisco, made the three runs seem like plenty.
“The best thing I saw was location,” Collins said. “[Niese] pounded the strike zone, you look and he’s got 85 pitches in the eighth inning and he’s strong instead of being 3-2 on a lot of guys.”
mpuma@nypost.com