Erik Karlsson scored the winner in the third period as the Ottawa Senators came from behind to beat the Montreal Canadiens 4-3 on Tuesday night to snap a two-game losing skid.
Mike Hoffman, Derick Brassard and Mark Stone also scored for the visiting Senators (11-7-1). Craig Anderson made 36 saves.
Shea Weber, Alexander Radulov and Alex Galchenyuk scored for Montreal (14-4-2). Andrei Markov had three assists while Carey Price stopped 19 of 23 shots in defeat.
Down 3-2 in the third, Stone tied things up from the slot after three Canadiens players got caught behind their own net.
Then Karlsson scored the winner at 5:37, the visitors' first lead of the evening, on a fluke no-look shot from the blue line after a bad giveaway by Jeff Petry.
The Sens scored more than two goals in regulation for the first time in 12 matches.
Montreal played with five defenceman in the third period after Nathan Beaulieu left the game at the end of the second. Beaulieu took a shot from Brassard to his neck and went straight to the dressing room.
The Canadiens later confirmed Beaulieu was taken to the hospital for precautionary reasons.
With Beaulieu's absence came extended ice times for Weber and Markov, Montreal's veteran defencemen.
After a sloppy first period by both teams, the goals came in quick succession in the second.
Weber got the Habs on the board 56 seconds into the period, on the power play. Hoffman took a penalty late in the first period for closing his hand on the puck, and Weber made him pay after the intermission with a thunderous slap shot from the point.
Seven of Weber's eight goals scored this season have been scored with the man advantage. Weber also has seven of Montreal's 15 power-play goals.
Hoffman got his redemption five minutes later. With Ottawa on the power play, the Sens winger beat Price above the shoulder from an extremely tight angle to make it 1-1.
The Canadiens regained their lead at 7:29 when Radulov scored after an impressive effort. The Russian dangled around Hoffman along the boards, cut to the net, shot on Anderson once then scored on his own rebound while falling to the ice.
Brassard tied things 2-2 late in the second before Galchenyuk answered back at 2:08 of the third.