Trailing, 3-1, after right winger/Bruins killer Tomas Vanek's second goal of the game 6:30 into the third period, the Bruins got goals from defenseman Dougie Hamilton, center Patrice Bergeron and right winger Reilly Smith in a 5:32 span to pull it out.
Smith, who also scored in Game 1, scored the winner with 3:32 left, giving goaltender Tuukka Rask his first career win in 10 home games against the rival Canadiens.
Left winger Milan Lucic hit the open net with 1:06 left.
The series shifts to Montreal for Games 3 and 4 on Tuesday and Thursday nights.
Left winger Brad Marchand, who coughed up the puck for the first Montreal goal, assisted on the first two goals in the late rally, with Bergeron assisting on Hamilton's goal before tying it with a deflection off defenseman Francis Bouillon.
Montreal goaltender Carey Price, who made 48 saves in the double-overtime victory in the opener, was the victim of the first three goals glancing off his defensemen -- two of them off Bouillon.
Rask made 25 saves to improve to 4-11-3 lifetime against Montreal.
Vanek, who has scored 30 goals in 55 regular-season games against Boston, scored on two power play deflections, lifting his team to the 3-1 lead. He tipped home both a pass and a shot from defenseman P.K. Subban, the Game 1 hero.
Vanek scored his team's third and fourth power play goals of the two games, against a Bruins penalty killing unit that was 18-for-20 in the first round against the Detroit Red Wings.
Price was keeping his team afloat when the Canadiens took a 2-1 lead on a 4-on-3 rush late in the second period.
Bruins defenseman Zdeno Chara's attempted clear was kept in by left winger Max Pacioretty, who got it to Subban. The defenseman's pass was then tipped in by Vanek at the top of the crease with 1:51 left in the period. Vanek tipped home a Subban rocket with 13:30 left.
The Bruins, who wasted an early 60-second 5-on-3 advantage, took a 1-0 lead 13:02 into the first period, with Paille actually starting the play with a strong back-check.
The puck wound up in the corner and center Carl Soderberg found Paille in the slot, which his screened shot glancing off the right skate of Bouillon and fluttering past Price.
The giveaway by Marchand led to the Canadiens tying the game 1:09 into the second. A flurry around the Boston net left Montreal left winger Brandon Prust on top of Rask, and Weaver scored on a slapper.
The Bruins had a goal disallowed back with 4:36 left in the second period when Lucic clearly gloved the puck into the net. For some reason, it was called a goal on the ice before being overturned upon quick review.Copyright © 2014, The Baltimore Sun