FORT MILL, S.C. — The Pawtucket Red Sox matched their longest losing streak of the season last night with a 4-2 loss to the Charlotte Knights in a pitcher’s duel that turned sour in the late innings.

Charlotte right-hander Charlie Haeger and three relief pitchers combined on a one-hitter to hand the PawSox (35-26), who fell short in a seventh-inning rally, their third straight setback.

“We didn’t put much of anything together against the knuckleballer [Haeger],” said Pawtucket hitting coach Russ Morman. “We had a chance at the end but couldn’t get the big hit.”

Morman ran the team for the last two-plus innings after PawSox manager Ron Johnson, along with designated hitter Bobby Kielty, were ejected in the seventh for arguing a called strike. Johnson appeared to inadvertently bump home-plate umpire Justin Vogel and flung his batting helmet down the right-field line as he headed for the PawSox dugout.

“The argument was about the strike zone and that’s about all you can say,” Morman said.

That’s not all the PawSox had to be frustrated about. The loss wasted a quality outing from starting pitcher Clay Buchholz, making his second appearance since being optioned from Boston on May 31. He allowed three hits in five scoreless innings.

“He did a nice job and kept us in the game,” Morman said.

But the PawSox, whose only hit came from a fourth-inning single by Jed Lowrie, didn’t give him any runs. They didn’t score until after the Knights grabbed a 4-0 lead, pounding relief pitcher Hunter Jones (1-2) for six hits in two innings.

In the seventh, the PawSox loaded the bases against Haeger, who hit Joe Thurston with a pitch and walked Lowrie and Brandon Moss to start the inning. Keith Ginter, pinch-hitting for Kielty after his ejection, drove in a run on a sacrifice fly to center field and added another when Sean Danielson walked with the bases loaded.

But Charlotte relief pitcher Mike MacDougal struck out Gil Velasquez and retired Jonathan Van Every on an infield out to end the game.