The Pittsburgh Pirates scored three runs in the eighth inning, one on relief ace Jesse Orosco's error and two on singles by Sixto Lezcano and Tony Pena, and ended a three-game losing streak by beating the New York Mets, 3-2, yesterday in New York.

Starter Ed Lynch had gotten the Mets a 2-0 lead after seven innings, holding the Pirates to three hits and no walks. He was lifted for a pinch hitter in the bottom of the inning.

Orosco (1-1) started the eighth by yielding a double to pinch hitter George Hendrick. Pinch hitter Jim Morrison walked and pinch hitter Bill Almon bunted toward third.

Orosco fielded the ball cleanly but his throw bounced past third baseman Ray Knight and rolled down the left field line, allowing Hendrick to score, Morrison went to third and Almon took second. Pinch hitter Lezcano and Pena singled consecutively for the tying and lead runs.

Pittsburgh's Larry McWilliams (2-1) worked seven innings, giving up both runs on eight hits before he left for a pinch hitter during the winning rally. John Candelaria faced six batters and got them all out for his fourth save.

Keith Hernandez, who had four singles in the game, led off the Mets' fourth with a single and went to third on a double by Gary Carter. One out later, John Christensen walked to load the bases and Danny Heep got a bad-hop single over first baseman Jason Thompson's glove, good for two runs.

It was the Mets' first loss in seven home games. They had allowed only two runs in their last five games at Shea Stadium.

"Lynch had had it," his manager, Dave Johnson, said, defending his decision to bat for him. "He started the game with a tender bicep. He pitched a great game."

"In my mind," Lynch said, "I wasn't tired . . . Maybe Davey felt I was. Davey's the manager. In his defense, he had his ace. You can't knock his decision. Maybe we're just spoiled now because Jesse has come through so often."

Is Lynch's arm "tender." "It didn't come from me," he said. He'd yielded a two-out triple to Steve Kemp in the seventh inning.