The goal came 7 seconds into the Canadiens’ second power play of overtime. Fans pelted the ice with cups and giveaway towels as the players filed off of the ice.
Carey Price stopped 48 shots for Montreal.
Tuukka Rask made 28 saves for the Bruins, who finished the regular season with the best record in the NHL but lost home-ice advantage with the defeat.
• Boston Mayor Martin Walsh and Montreal Mayor Denis Coderre have a wager on the series.
Walsh said the winning mayor will play host to the series loser for a visit, and the winning city’s team flag will fly at the loser’s city hall.
The teams are two of the league’s original six franchises.
CANUCKS: Fired John Tortorella one year into the fiery coach’s long-term deal.
Tortorella, who signed a five-year contract last summer after being dismissed by the New York Rangers, failed to reach the playoffs behind the Vancouver bench.
Assistant coach Mike Sullivan was also fired Thursday.
The Canucks finished 25th in the 30-team NHL. It was Vancouver's worst finish in 14 years and came just three seasons after former coach Alain Vigneault led the Canucks to Game 7 of the 2011 Stanley Cup finals.
Vigneault replaced Tortorella as coach of the Rangers and advanced to the second round of the playoffs on Wednesday with a Game 7 win over Philadelphia.
Tortorella’s dismissal comes just weeks after general manager Mike Gillis was fired. The Canucks then named former captain Trevor Linden as team president.
ISLANDERS: Acquired the negotiating rights to veteran goalie Jaroslav Halak from the Washington Capitals on Thursday for a fourth-round pick in a trade between teams that failed to make the playoffs.
New York is sending the draft pick it acquired from Chicago in February in the deal that sent Pierre-Marc Bouchard and Peter Regin to the Blackhawks.
If a new contract isn’t reached with Halak before July 1, the 28-year-old goalie can become an unrestricted free agent.
Halak is 144-85-29 with a 2.38 goals-against average in his NHL career.
HART TROPHY: Pittsburgh’s Sidney Crosby, Anaheim’s Ryan Getzlaf and Philadelphia’s Claude Giroux are finalists for the award, which essentially serves as the league’s MVP award.
The Professional Hockey Writers’ Association submits ballots.
Crosby scored 36 goals and led the league in assists (68) and points (104), guiding the Penguins to their second consecutive division title.
Getzlaf scored a career-high 31 goals and ranked second in the League with 87 points, leading the Ducks to the top record in the Western Conference for the first time in franchise history.
Giroux matched a career high with 28 goals and finished third in the NHL scoring race (86 points).
The winner will be announced June 24.