Simon Gagne scored on a power play with 7:08 left to cap a comeback from a three-goal deficit, and the Flyers won 4-3 on Thursday night for a berth in the Eastern Conference finals that seemed a distant dream after they lost the first three games.
For the Bruins, the season will be remembered for the colossal collapse. They're only the third team in NHL history to lose a series after winning the first three games.
And now the seventh-seeded Flyers get to start the next round at home Sunday night against another surprising conference finalist, the eighth-seeded Montreal Canadiens.
Gagne, a major force since returning from a toe injury for Game 4, scored with only 18 seconds left in a power play after the Bruins were penalized for having too many men on the ice.
Too many men and too few goals for Boston.
The Flyers capitalized when captain Mike Richards' shot from the right circle hit players in front of Tuukka Rask. The puck bounced and Gagne, stationed to Rask's left, flipped the puck over the goalie's right shoulder.
The only other teams to win a series after trailing 3-0 were the 1942 Toronto Maple Leafs, who beat Detroit, and the 1975 New York Islanders, who eliminated Pittsburgh. The other 159 teams that won the first three games in a series all won them.
The Bruins shot out to a 3-0 lead on power-play goals by Michael Ryder and Milan Lucic and another goal by Lucic. And only 14:10 had been played. Then James van Riemsdyk scored with 2:48 left in the first period before second-period goals by Scott Hartnell at 2:49 and Danny Briere at 8:39 tied it.
Boston lost its third straight Game 7 and first since falling to Carolina in last year's conference semifinals after battling back from a 3-1 series deficit.
Spurred on by a loud crowd waving yellow Bruins towels, the home team played aggressively at the start. But so did the Flyers. There was plenty of end-to-end action in the first 5 minutes.
Then the Bruins got a break when Hartnell was penalized for high-sticking at 5:19 and Ryder scored his fourth playoff goal on a rebound eight seconds later. Another Boston power play three minutes later led to another goal, this one by Lucic, who tipped in a pass across the crease from Dennis Wideman in the right corner.
Lucic struck again, scoring his fifth playoff goal five minutes later, at 14:10 on a shot from the right circle.
Another 3-0 lead. Another load of trouble ahead.
Flyers goalie Michael Leighton, who took over in Game 5 when Brian Boucher sprained the medial collateral ligament in his left knee, didn't let another goal past him.
Van Riemsdyk began the comeback with his first playoff goal 3 minutes after Lucic's second goal on a soft shot that trickled by Rask. That was the first of nine consecutive shots by Philadelphia. One of them was Hartnell's second goal of the playoffs. Another was Briere's seventh playoff goal — on a wraparound.
There were no more goals — until Gagne sent the Bruins into an offseason wondering how it all fell apart.
And when the final buzzer sounded, those towels made another appearance, flying to the ice after being tossed by frustrated Bruins fans.
Patriots coach Bill Belichick attended the game. … Philadelphia beat second-seeded New Jersey in the first round, while Boston eliminated third-seeded Buffalo. … The Flyers are 8-6 in seventh games. The Bruins are 9-10.