Updated

By Ros Krasny

BOSTON (Reuters) - The Philadelphia Flyers, having fought back from a 3-0 series deficit, beat the Boston Bruins in a decisive seventh game Friday, setting up an unlikely showdown in the NHL's Eastern Conference finals.

With the 4-3 win in Game Seven, the Flyers became just the third team, and the first since the New York Islanders in 1975, to win a best-of-seven series after trailing 3-0.

The Flyers now return home to open the Eastern Conference final Sunday against the Montreal Canadiens.

Philadelphia and Montreal are the lowest seeds to qualify for the playoffs in the Eastern Conference. Neither team was expected to get out of the first round.

"It's an unbelievable feeling. The hearts are racing. There is just excitement on everyone's face, and the confidence we have now is huge. But our opponents are in the same boat," Philadelphia's Scott Hartnell told reporters.

Simon Gagne's power-play goal from 25 feet clinched the win for Philadelphia with about seven minutes to play, at a time Boston was a man short because of a penalty for having had too many men on the ice.

"Simon is a pure goal scorer. When he's on, he's hard to stop," said Laviolette.

Friday's game was like a microcosm of the series. Boston jumped off to a 3-0 start in the first period before being reeled in and, finally, overtaken.

The Bruins started with guns blazing. Michael Ryder scored about five minutes into the game and Milan Lucic added a pair, including an unassisted snap shot past Philadelphia goalie Michael Leighton, to give the Bruins a three-goal cushion.

Laviolette quickly called a time-out. "The time-out was just to try to slow things down, to get us back in there. The message was just 'score one goal, get in the game,'" he said.

Philadelphia's James van Riemsdyk got one back before the end of the period with a 30-foot wristshot past Boston goalie Tuukka Rask. Scott Hartnell and Danny Briere scored in the second period to tie the game, and shake up the rhythm of the home team.

"In the second period we got back into it. We were moving our feet, we were hitting," Hartnell said.

The Flyers outshot Boston by 27 to 25. The home team took only 11 shots on goal in the final two periods.

Boston has been hurting offensively since losing David Krejci, its equal top points scorer in the regular season and regarded by many as the team's top player, to injury in Game Three of the Philadelphia series.

But Bruins coach Claude Julien refused to make excuses.

"I'd rather grow from this and take the responsibility as a coach. It's not too often that excuses get you to where you want to get, and we want to get better," Julien said.

"We weren't able to finish, and that's the most disappointing thing right now. The team that won tonight deserved it."

(Editing by Frank Pingue)