It was the first time in the four games played thus far that a team has won by more than one goal. With the Eastern Conference semifinal duel tied at 2-2, Washington will host Game 5 Saturday.
The Penguins overcame an early 1-0 deficit with consecutive goals from Sergei Gonchar, Bill Guerin and Fedotenko in the first period. The win was tempered, however, by the loss of Gonchar during the game with a knee injury.
He collided knee-to-knee with Washington star Alexander Ovechkin with five minutes left in the first period. As Gonchar skated from behind the Washington net, Ovechkin appeared to extend his right knee a moment before the collision.
Ovechkin was handed a two-minute tripping penalty and Gonchar had to be assisted to the locker room, unable to put any weight on the leg.
Chris Clark, Nicklas Backstrom and Milan Jurcina all scored for the Capitals, while Simeon Varlamov allowed all five goals on 28 shots.
Marc-Andre Fleury had to make only 19 saves to get the win.
Crosby has nine goals and seven assists in the playoffs. He and Anaheim's Ryan Getzlaf are tied for most points in the post-season with 16.