Pacioretty scored the tiebreaking goal late in the third, and the Montreal Canadiens beat the Colorado Avalanche 4-3 Monday night.
P.K. Subban and Andrei Markov each had a goal and an assist, and Jiri Sekac also scored for Montreal, which ended a three-game losing streak. Carey Price made 26 saves.
Pacioretty had a breakaway chance in the first period that was saved by Calvin Pickard but made the most of his second opportunity. Pacioretty skated in on the left side and thought about passing to linemate Dale Weise before beating the rookie goalie with a snap shot with 6:06 left.
"I'm looking to get Weise a goal there," Pacioretty said. "But at the end of the day, if we don't bury it, I'm coming back to the bench upset with myself."
It was his team-leading 12th goal of the season.
"It was a great shot by a great player, but I've been playing pretty well and I really wanted to get that to overtime at the very least," Pickard said. "Definitely a good shot, but I definitely would have liked to make the save for the team."
Ryan O'Reilly, Daniel Briere and Tyson Barrie scored goals, and Pickard had 26 saves for Colorado. The Avalanche (9-11-5) failed for the sixth time to get back to the .500 mark.
"We're not going to quit," Briere said. "We have to go right back at it, get a win in Calgary and give ourselves another shot."
The Avalanche took their first lead with a pair of goals spanning the first and second periods. Briere tied it 1-all when he stole the puck from Lars Eller and beat Price with 34 seconds left in the first.
O'Reilly made it 2-1 with his fourth goal 35 seconds into the second.
Montreal, which outshot Colorado 18-9 in the middle frame, got goals from Markov and Subban in the period to go into the third tied at 3. Markov's power-play goal tied it 2-all, and Subban's came 3:15 after Barrie gave Colorado a 3-2 lead with a shot that went off the stick of Canadiens forward Brandon Prust.
"Whether we're up one goal or down one, we don't panic," Subban said. "I think that's one of the big keys to having a successful team, and hopefully that leads to the post-season and goes deep into the post-season. You can't get too high, you can't get too low, and I think we do a great job of sticking together."
The Avalanche nearly had three goals in the second period, but Matt Duchene's shot from the right circle rattled off both posts before Price covered the puck.
"I heard the initial post and I thought I heard a second post," Price said. "I felt it land between my legs. Got lucky."
Sekac opened the scoring with his fourth goal at 8:09 of the first.
NOTES: Linesman Derek Amell skated off with the help of a Colorado trainer after hitting the ice hard with 8:13 left in the third. Amell returned later in the period. ... The Avalanche recalled centres Michael Sgarbossa and Colin Smith from Lake Erie of the AHL. The played in place of centres Marc-Andre Cliche (oblique) and John Mitchell (leg). ... Montreal RW Pierre-Alexandre Parenteau returned to Colorado for the first time since being traded by the Avalanche this summer. ... Smith played in his first NHL game Monday.