MONTREAL -- Alex Galchenyuk had a few chipped front teeth after taking a stick to the mouth Saturday, and he soon got an opportunity to display his new crooked smile.
Galchenyuk, who set up Brendan Gallagher's go-ahead goal in the second period, finished defenseman Alexei Emelin's pass to put Montreal ahead by three at 17:34 of the third, 44 seconds after Tomas Plekanec's power-play goal made it 3-1.
"[Pacioretty] and [Emelin] made a great play and I was just in the spot, and I had to tap it in; Christmas for me," said Galchenyuk, who was grinning in the dressing room despite an impending visit to the dentist after he was struck in the mouth by an errant stick earlier in the third.
"We play in a really tough division," Canadiens coach Michel Therrien said. "A lot of teams got a lot of success, so we knew it was important to get four wins out of five. So you've got to look at the big picture, and we're satisfied."
Pacioretty was in Montreal's lineup after leaving early in the third period of the Canadiens' 2-1 loss to the Anaheim Ducks on Thursday with an upper-body injury after he fell headfirst into the boards on a hit by Clayton Stoner.
Gallagher put Montreal ahead 2-1 with his ninth goal at 7:30 of the second period, finishing a passing play with Pacioretty and Galchenyuk.
"I had the easy part on the goal," Gallagher said. "[Pacioretty] made a great play to [Galchenyuk] and then I knew [Galchenyuk] was giving it back to me, and he found a small hole, so it was pretty easy and a great play by them."
Plekanec made it 3-1 with a power-play goal at 16:50 of the third, and Galchenyuk scored his 10th within a minute.
"You can't give this team too much open space," Lehner said. "I think they're too skilled and they'll take advantage, but I think we played solid. Obviously the last two goals happened fast in the end and I don't think that reflects the game. I think we battled hard and played better."
The Senators went 0-for-3 with one shot on the power play. Ottawa was called for too many men on the ice at 15:56 of the third period.
"We generated absolutely nothing off of the power play, not even momentum, and we knew they were going to get wind with a big (penalty) kill," Senators coach Dave Cameron said. "And too many men on the ice, and now we started chasing; we opened up a little bit."
Condra scored his second goal to put Ottawa up 1-0 at 2:50 of the first period. The forward took a wrist shot from outside the blue line that Price stopped, but he lost sight of the puck when it dropped between his pads and it was behind him.
With Montreal defenseman Andrei Markov covering him, Condra drove to the net and lunged with his stick to put the loose puck into the net.
"That was a pretty embarrassing moment, but at the end of the day you've got to just put it behind you and look forward to the next shot really," Price said.
Prust drew the Canadiens even at 1-1 with his third goal at 6:38 of the first on a shot from the right corner for his 100th point.
Lehner moved to cover his angle when Prust took a pass from Montreal defenseman Tom Gilbert. Prust held the puck before taking a wrist shot that found its way across the goal line between Lehner and the right post. A video review confirmed the on-ice ruling that the puck had entered the net.