The second time through the Milwaukee Brewers batting order, Charlie Morton began to falter.
Morton's quick work in the first three innings gave way to an uneven final three as his command wavered.
The Brewers scored five runs in the latter half of Morton's start, three in the fourth, on their way to a 5-3 win against the Pirates Friday night at PNC Park in front of 31,564.
The night also featured an injury to shortstop Jordy Mercer that forced him from the game and a baseball that disintegrated after it was struck.
The Pirates have lost three of their past four games and six of eight.
Morton (0-2) allowed five runs on eight hits in six innings on a night when he struggled with his control.
His curveball came and went.
Carlos Gomez, the game's first batter, watched one for strike three and broke his bat over his knee in frustration. Later, Morton threw a curveball behind Jean Segura and hit Aramis Ramirez with another.
"Not making pitches when I needed to make pitches, especially in the fourth inning," Morton said.
"There was a big momentum shift. They put three runs up on the board."
The starters have struggled early in 2014. They entered the game with a 4.13 ERA, which ranked 10th in the National League.
Pedro Alvarez stranded eight runners. He came to the plate with the bases loaded in the third, two on in each the fifth and seventh, and one in the ninth, but could not drive them home.
"We just weren't able to get that at-bat when we needed," manager Clint Hurdle said.
Brewers starter Kyle Lohse (3-1) allowed three runs, one earned, in 61/3 innings.
Starling Marte reached base on an error to start the first. He stole second, forcing a throw, and Martin Maldonado threw the ball away to send Marte to third.
Russell Martin's grounder scored Marte.
Maldonado worked a leadoff walk in the third. When advancing to second on Kyle Lohse's bunt, Maldonado slid into Mercer's right ankle as Mercer recorded the forceout. Mercer immediately hopped off that leg, in obvious pain, and the team converged on him while a member of the training staff examined him.
Mercer said Maldonado slid into him just above the right ankle, which was better than had it hit the joint. He also said the ankle did not roll or twist; the pain came from the blunt-force impact.
Mercer stayed in the game. He led off the bottom half of the inning and scored on Martin's RBI single, but Clint Barmes replaced him at shortstop in the fourth.
"I couldn't feel any explosion when you push off," Mercer said.
"I wanted to be able to move. That whole trip around the bases I was trying to loosen it up, trying to figure out something."
Morton worked quickly through the lineup until the fourth. He allowed a leadoff double to Ryan Braun before walking Ramirez and hitting Khris Davis. Mark Reynolds flied out, but Scooter Gennett, the one left-hander in the Brewers lineup, hit a two-run double. Jose Tabata and Neil Walker cut down Davis at the plate to save a run, but the hit tied the score.
"Scooter got a chance there with the bases loaded, 0-0," Morton said. "He was sitting dead-red [fastball]. Drove it into the gap."
Maldonado's single scored Gennett to give the Brewers a 3-2 lead.
Gomez hit a solo home run to lead off the fifth and an RBI single in the sixth. Maldonado's grounder to third in the sixth unstitched the baseball, allowing the cover to flap open. When Alvarez threw it to first, it fluttered like a wounded bird and died halfway across the infield, gift-wrapping Maldonado a single. The Brewers would score a run later that inning. Hurdle said he had never seen the cover come off the ball.
The Pirates had a shot in the eighth when Will Smith hit Walker, pinch-hitter Josh Harrison singled and Travis Snider walked to load the bases, but Marte popped out.
Bill Brink: email@example.com and Twitter @BrinkPG.
Bill Brink: firstname.lastname@example.org and on Twitter @BrinkPG.