The Montreal Canadiens took advantage of that Sunday night, scoring twice in the third period while Chara was serving out a minor for instigating, a fighting major and a 10-minute misconduct to earn a 4-3 comeback victory against the Bruins at TD Garden.
Chara was assessed 17 minutes in penalties for instigating a fight with Montreal defenseman Alexei Emelin with five minutes to play in the second period. Chara took offense to a hit Emelin had thrown at Tyler Seguin moments earlier in the neutral zone.
"It's big, [he's] a big player for them, he's great -- power play, PK, 5-on-5. He's a big part of their team and for him to not be there for  minutes was huge for us and we took advantage of that," Desharnais said.
Though the Bruins could ill afford to lose their captain and one of the League's best defensemen, Chara had just witnessed Emelin break his stick while checking Seguin. The Boston forward looked shaken up and left the ice for several seconds before returning.
"Yeah, I mean obviously the guy just broke his stick cross-checking Tyler, and when he went down I was just reacting to it, but he's one of our best players and I'm not going to just watch him getting crushed like that," Chara said.
Bruins coach Claude Julien said it was frustrating to lose Chara instead of being on the power play. Julien's anger boiled over postgame, and he expressed his disdain for the way he thinks the Canadiens play.
"It's frustrating because tonight as everybody saw, there's a lot of embellishment," said Julien, whose team was shorthanded five times to Montreal's two. "And this is embarrassing for our game, the embellishing. And right now they've got over 100 power plays, so far, and it's pretty obvious why. And we're trying to clean that out of our game. And it's got to be done soon because it's not about tonight, it's about the game. And embellishment embarrasses our game. And we need to be better at that."
The game between the top two teams in the Eastern Conference featured plenty of offensive and physical fireworks. There were 48 penalty minutes, including a fight between Boston's Milan Lucic and Montreal's Brandon Prust in the second period, which impressed Canadiens coach Michel Therrien.
"What Brandon Prust did for this hockey team, I'll call that great leadership," Therrien said. "I was going to make sure that players knew between the second and third that we have to respond as a team, and I thought we responded the right way."
Down 3-2 to start the third, Montreal tied the game at 5:31 when Pacioretty's wrist shot from the high slot hit something and eluded goaltender Tuukka Rask (22 saves). Desharnais then scored the winner during a scramble in front after a wide shot by Brendan Gallagher and a pass to the crease by Pacioretty.
"It just bounced on my stick there. And it was a lucky one," Desharnais said.
Montreal goalie Peter Budaj, making his first start since Feb. 18, finished with 31 saves. The Canadiens decided to go with their backup after Carey Price lost to the Pittsburgh Penguins, 7-6, Saturday night.
Budaj stopped all 10 shots he faced in the third period.
"He played well. He deserved to be there tonight," Therrien said. "That's the way we saw it. ... We can't forget that when Carey was sick, [Budaj] played two fantastic games for us and only allowed one goal in two games. The way he is working hard during practice, he deserved to play tonight and it was a great challenge for him. He made some key saves at the right time."
Montreal jumped out to a 1-0 lead on a Tomas Plekanec power-play goal 9:57 into the game. Seguin answered at 10:47, but Desharnais' pass to the front deflected in off a Boston skate to put Montreal back ahead 16 seconds later.
The Bruins scored the only goals in the second period. Patrice Bergeron benefited from Andrei Markov kicking in a loose puck at 4:06. Then Dougie Hamilton one-timed a bouncing puck over Budaj's shoulder into the top of the net for a 3-2 Boston lead with 9:20 gone in the middle session.
Montreal is two points ahead of Boston for first place in the East with the Bruins holding three games in hand. Expectations were low for the Canadiens, but Montreal has split its first two meetings with the two-time defending Northeast Division champion Bruins.
"Well we are coming a long way," Therrien said. "We believe that if we stick to our plan we have a chance to win every game. That's the way we approach the game. Like tonight, we had a great start in the first period and guys are confident. They know that if we stick to our plan, we have the chance to win."