Jaromir Jagr had the first three-goal game of his NHL career, but Mario Lemieux was injured again yesterday as the Penguins beat the Boston Bruins, 6-2, in Pittsburgh.

Lemieux, who returned last Saturday after missing 50 games with back problems, abruptly went out with 14:56 left in the second period with a pulled groin. He is out at least until Friday.

"He said someone hooked him and he felt a strain and almost a little pop," team physician Charles Burke said. "It's tender in his groin but radiates all the way around his hip. It doesn't appear to have anything to do with his back."

After an infection in his back was diagnosed in September, Lemieux was put on a program of antibiotics and rest. He started light exercises in mid-December and skating Dec. 30. He had two goals and four assists in his first two games. "He's still in the training camp-type time frame," Burke said. "These types of pulls and strains happen in camp."

Jagr, who'd gone nine games without a goal, scored on Pittsburgh's first power play, deflecting Larry Murphy's shot from the blueline at 9:19. In the second, Paul Coffey carried the puck from behind his net to the faceoff circle. Jagr took his pass, weaving through the defense to shoot past Norm Foster's stick. He got his third goal on a third-period breakaway.