Guillaume Latendresse scored late in the second period to give Montreal its fourth lead, and Roman Hamrlik, Mike Komisarek and Alexei Kovalev added third-period goals to lift the Canadiens to a 7-4 win over Boston on Saturday.
Saku Koivu, Tom Kostopoulos and Andrei Kostitsyn scored to give Montreal its first three one-goal leads.
Glen Murray, Chara and Marco Sturm answered for the Bruins.
Latendresse put the Canadiens ahead 4-3 with 2:30 remaining in the second period when he put his rebound over Tim Thomas' left pad for his third goal of the season.
"It seemed like we'd get the lead and then make one big mistake and let them score," said Hamrlik, who gave Montreal a 5-3 edge with his second goal during 4-on-4 play 4:23 into the third. "We knew we didn't want to change anything after the second period and we came out hard."
Komisarek increased the margin to 6-3 with his third goal at 10:15.
Murray drew the Bruins within 6-4 with his second of the game at 11:07 off a faceoff immediately after Canadiens coach Guy Carbonneau and assistant Kirk Muller exchanged heated words with Boston head coach Claude Julien.
Bruins defenseman Mark Stuart won a lopsided fight with Kostitsyn at 11:05.
"You work hard for 50 minutes to take the lead and get ahead of the other team, and then you have to deal with things like that," Carbonneau said. "Those aren't things I like to see but that's part of the emotion, part of the rivalry. I'm going to try to protect my players and my bench, and Claude is going to do the same thing with his bench."
Julien insisted his players didn't carry over anything from the teams' previous meeting when Boston's Aaron Ward sustained a concussion from Francis Bouillon unpenalized hit.
Ward missed two games, and the NHL chose not to penalize Bouillon following a review.
"All I know is that somehow they seemed to be accusing me of obviously sending someone to do something but it's certainly not my style, I've never done it in my life," Julien said. "Kostitsyn spears Stuart, so Stuart drops his gloves. I know Kostitsyn's not a fighter, but I didn't stand up on the bench and accuse Carbonneau of sending Bouillon to elbow Ward so I think it's just a matter of, 'Take care of your own business, and we'll take care of our own."'
Chara went to the dressing room amid a cheer from the sellout crowd of 21,273 when he was summoned from the penalty box after he was given 19 minutes in penalties for elbowing Kovalev and instigating a fight with Latendresse at 13:26.
"It wasn't an elbow," Chara said. "Kovalev ducked. I went to hit him and he ducked."
Kovalev scored his 10th goal at 14:12 to restore Montreal's three-goal lead.
Boston was assessed 42 of 78 penalty minutes doled out in the third by referees Dan O'Rourke and Dean Warren.
"I think it was a lot of frustration built up in our team, not playing the way we know we're capable of playing and the mistakes that we made, knowing that we haven't made those mistakes hardly at all this year," Murray said. "We made four or five and they capitalized on all of them."
Rookie Carey Price stopped 32 shots for the Canadiens, who have won four of six despite a 4-1 loss in Buffalo on Friday.
"It was a pretty entertaining game," Price said. "I think it was a pretty fun game to watch for a fan. It had pretty much everything in it."
Thomas made 45 saves for the Bruins, who had won two in a row following a four-game losing streak (0-2-2).
"He's played great for us the whole season, no question about it," Murray said. "You can't fault him on what happened. He's kept us in every game all year and we didn't bail him out tonight."
Koivu opened the scoring 2:40 in with his fifth goal on a power play, the only tally of the opening period.
Montreal took a 3-2 lead on Kostitsyn's third goal of the season 4:59 into the second as the teams combined for three goals 3:50 apart early in the period.
Kostopoulos scored his second goal of the season with a short-handed tally 1:19 into the second.
Chara tied it at 2 with his first goal of the season on a one-timer from the right side at 3:11.
Sturm extended his goal streak to four games midway through the second when he scored his ninth of the season on a power play to tie it at 3.
Chara was one of five Bruins sitting side by side in the penalty box before he was sent to the dressing room. ... Both of Kostopoulos' goals this season were short-handed markers. ... D Patrice Brisebois and LW Mikhail Grabovski were healthy scratches for Montreal.