Mandatory Credit: Wendell Cruz-USA TODAY Sports

Entering their league-leading 10 doubleheader on Saturday, the Mets were among the best in the majors both in first games of twin bills and contests in which they scored first.

Neither would end up mattering however, as the Pirates came from behind to down the Mets 6-2 in the first of two seven-inning games at Citi Field.

Tyler Anderson pitched well through five innings for Pittsburgh and added a go-ahead homer in the win. The loss moved the Mets to 35-10 when scoring first and 8-2 in doubleheader openers.

Brandon Nimmo had himself quite the first inning. First, he went over the fence in center field to bring back what would have been a home run off the bat of Bryan Reynolds for the final out in the top of the frame.

He followed that up with a leadoff single in the bottom half of the inning, and after advancing to third on Dom Smith’s single, scored the game’s first run on Kevin Pillar’s two-out liner into left field.

Armed with a 1-0 lead in the second, Marcus Stroman downed the Pirates in order via a weak groundout to first, a strikeout and a shallow pop up to left. Anderson responded in kind, sending the Mets away in the bottom of the inning despite an opposite-field single from Tomas Nido.

Stroman coaxed grounders to first and second and struck out his counterpart to make it through three perfect innings. Anderson likewise was able to retire the Mets in order, getting Francisco Lindor and Pete Alonso to fly out around a Smith groundout.

Adam Frazier started Stroman’s second time through the order with a single to left for Pittsburgh’s first hit of the afternoon. With one out, he moved to third on Reynolds’ bloop into right center. Stroman struck out Ben Gamel for the second out, but John Nogowski ripped a 3-1 sinker just past the diving glove of Jonathan Villar and down the left field line – scoring both runners and giving the Pirates a 2-1 lead at the midpoint of the seven-inning affair.

Jonathan Villar didn’t waste much time in tying it up in the fourth, hitting his third homer in the last two days over the Great Wall of Flushing to knot the game at two.

After a single and double play gave the Pirates two outs and nobody on with the pitcher up, it seemed as if Stroman and the Mets were in good shape. Anderson showed bunt on the first two pitches of his at bat and then decided to swing away, bashing one over the right field wall to put the Buccos up 3-2 midway through the fifth.

Jeff McNeil pinch hit for Stroman in the bottom of the inning and laced a single into left. From there, Nimmo grounded into a fielder’s choice, Lindor popped out and Smith flew out to get Anderson through the inning unscathed.

Trevor May took over for Stroman in the top of the sixth, making it three straight starts in which Stroman has failed to go more than five innings. May walked Ke’Bryan Hayes to lead off the frame, and Reynolds hit another one over the wall – this time far enough that no one could catch it – to give the Pirates a three-run lead.

May labored for the rest of the sixth – allowing a hit and a walk – but escaped without allowing another run.

David Bednar entered for the Pirates with a 5-2 lead and struck out Alonso on four pitches. Pillar reached on an infield single (that was really an error) but flyouts from Villar and pinch-hitter Michael Conforto left him at first.

Drew Smith entered for the seventh inning and was greeted with a Jared Oliva single through the shift. He stole second and scored on a hustle double from Hayes to extend the Pirate lead to four. After an intentional walk to Reynolds, Smith struck out Gamel and Nogowski flew out to left to end the frame.

Pirate closer and fastball machine Richard Rodriguez entered for the seventh to face pinch-hitter Billy McKinney. Rodriguez disposed of McKinney on four pitches, getting him looking at a high fastball. McNeil fouled out to third and Nimmo struck out on a slider at his foot to end the game.

The Mets will look for a Saturday split with Tylor Megill on the mound, making his fourth career start. He’s opposed by Pittsburgh’s Max Kranick, making just his second start. In his first career appearance two weeks ago, Kranick went five perfect innings against the Cardinals before being removed. The game can be watched on SNY around 7 p.m.