William Nylander scored and Joseph Woll made 30 saves for Toronto (27-27-11), which is on a 0-6-2 skid.
“It’s a lot of losses in a row now,” Nylander said. “I think parts of all the games we’ve been playing, we’ve been playing snippets of good hockey, and that’s not how we want to play. We want to play a full game of good hockey.”
The Maple Leafs, who have not missed the Stanley Cup Playoffs since 2015-16, are at .500 for the first time since they were 15-15-5 following a 5-1 loss at the Dallas Stars on Dec. 21.
The Canadiens outshot Toronto 33-18, including 18-5 while taking a 2-0 lead in the first period.
“They definitely had the play in the first for sure, had the puck,” Maple Leafs coach Craig Berube said. “You know, we didn’t check it off them, and then when we did, we didn’t do anything with the puck. We couldn’t get up the ice as a five-man unit and create anything.”
Kapanen put Montreal up 1-0 at 4:46. After helping Ivan Demidov win a puck battle in the left corner, he went to the left of the net to take a pass from Alex Newhook before spinning to his right and putting a snap shot between Woll’s pads.
“Everyone was in his spot, so we just tried to find each other and help each other out,” Demidov said.