Price bounced back from the worst outing of his career and posted his 10th NHL shutout. The 23-year-old Price, who has two shutouts in his last four starts, allowed a career-high eight goals and fought with fellow All-Star goalie Tim Thomas in an 8-6 loss at Boston on Wednesday night.
Thomas and New York Rangers goalie Henrik Lundqvist are tied for the league lead with seven shutouts.
Pouliot scored for a second game in a row 10:12 into the second. Gionta made it 2-0 moments later with his team-leading 21st goal. David Desharnais, who assisted on Pouliot's goal, scored during a third period power play. Roman Hamrlik earned his second assist.
Jean-Sebastien Giguere stopped 36 shots in his second start in six games for Toronto, which dropped its second in a row. The Leafs' shootout loss to New Jersey on Thursday followed a 4-1 run.
Phil Kessel's goal-scoring drought reached 14 games. The Toronto right winger, who was the last player selected in the All-Star game draft, has been held to five assists over that span.
Pouliot opened the scoring when he snapped a shot past Giguere after he was left alone in the slot. He one-timed Desharnais' backhanded pass from behind the net.
Gionta put Montreal up 2-0 at 11:52. The Canadiens captain put a shot past Giguere after Max Pacioretty got off a backhanded pass from the left side of the net while being knocked to the ice by defenseman Luke Schenn.
Desharnais increased the lead to three with his fifth goal 6:19 into the third. The rookie center drove the left side to and redirected Scott Gomez's return pass beyond Giguere.
Pacioretty left the game later in the third after he was checked into the boards by Schenn.
Canadiens defenseman P.K. Subban fought late in the first with Toronto's Joffrey Lupul, who played his second game since being acquired from Anaheim on Wednesday.
Notes: Maple Leafs G Jonas Gustavsson had heart surgery on Friday to help treat a condition causing an abnormal rhythm. Gustavsson was on a minor league conditioning stint when he was pulled from the AHL Toronto Marlies' game because of an elevated heart rate. He is expected to be cleared for practice at the end of the week. ... Canadiens D Hal Gill (upper-body injury) and LW Mathieu Darche (lower-body injury) both missed their second straight game.