BEDFORD, Mass. — The Boston Bruins thought they excised the specter of last season’s postseason collapse when they finished off the Philadelphia Flyers in the Eastern Conference semifinals this year.

Yet here they are again, one round later, trying to turn back another comeback.

The Bruins will play the Tampa Bay Lightning in Game 7 of the conference finals on Friday night, with the winner earning a chance to play the Vancouver Canucks for the Stanley Cup. But Boston could have avoided a winner-take-all predicament if it had merely protected a three-goal lead in Game 4; scored more than one power-play goal a week in the playoffs; or kept Tampa Bay from scoring, as often as not, in the first 90 seconds of the game.

“We’ve got a Game 7, it’s at home, and we’re one game away from the Stanley Cup finals. Why shouldn’t we be excited?” coach Claude Julien said Thursday after stepping off the team charter at Hanscom Field outside of Boston. “Our guys are not discouraged or disappointed. The past is the past. We’ve got an opportunity to win a hockey game and get into the Stanley Cup finals.”

The Bruins spent most of this season trying to forget what happened in last year’s playoffs, when the Flyers rallied from a 3-0 deficit to force a seventh game and then trailed 3-0 in Game 7 before winning to advance to the conference finals. Boston swept Philadelphia this year in Round 2, but that doesn’t mean Bruins fans are ready to get comfortable when the team gets a big lead.

In Game 4, with Boston already leading the series 2-1, the Bruins opened up a 3-0 lead before allowing five unanswered goals. The Bruins also led 3-2 in the series, with a 2-1 lead after one period of Game 6 on Wednesday night, before the Lightning scored three in a row and eventually won 5-4.

That sent the teams back to Boston for Game 7.

“When it all comes down to one game, I think the pressure is on both teams,” Bruins forward Patrice Bergeron said. “You shouldn’t allow pressure to get into your head. Just go out there and play your game.”

Although the Bruins can call upon their experience in Game 7 against Montreal in the first round, Tampa Bay is much more familiar with elimination games. The Lightning fell behind the Pittsburgh Penguins 3-1 in the first round before winning three straight to advance; Wednesday’s victory over Boston made them 4-0 this season in elimination games; and goalie Dwayne Roloson is 7-0 in his career when facing elimination.

“When we face elimination, you want to play on your best, and that’s what we want to bring all the time,” Tampa Bay defenseman Victor Hedman said. “Come playoff time, every game is a live-or-die moment, especially when you’re facing elimination.”

Although the teams finished the regular season with identical 46-25-11 records, good for 103 points, the Bruins have the home-ice advantage for Game 7 because they won the Northeast Division while the Lightning finished behind Washington in the Southeast.

“We worked all year to have home ice, and now we have to take advantage of it,” Bergeron said. “We can’t worry about what happened in the first six games.”

The upstart Lightning, who began play in 1992, may have one advantage: They have never lost in three previous Game 7s, one of them against the Calgary Flames in the 2004 Stanley Cup finals. Boston, an Original Six team that hasn’t won the Cup since 1972, is 10-10 in Game 7s.

“I think that’s what you play for,” Lightning forward Martin St. Louis said. “Whether it’s as a kid in the driveway and pretending to be a Game 7, those are the games you watch as a kid. Those are the games that get your fire going, and those are the ones you want to play in. The do-or-die games. Our back’s against the wall. You want to leave it out there.”