"The best way to describe him was very complete," Maple Leafs coach Sheldon Keefe said. "He was extremely competitive, physical on the puck, scored a huge goal for us, played with all sorts of authority, strong in the face-off dot (winning 16 of 20). There wasn't really anything he didn't do extremely well today. We had good efforts all throughout our lineup, but there's no question Auston was a difference-maker."
The Maple Leafs were without captain John Tavares, who sustained a concussion and a knee injury in Game 1 on Thursday. The forward is out indefinitely.
"It means a lot not only for the guys in the locker room but for John himself," Matthews said. "He's such a big part of this team, he's our leader. When something really scary and serious goes down like it did the other night, I think the response from our group was unbelievable tonight."
Rasmus Sandin scored his first Stanley Cup Playoff goal, William Nylander had a goal and an assist, and Jack Campbell got his first NHL postseason win by making 22 saves for the Maple Leafs, the No. 1 seed in the Scotia North Division.
Toronto had lost nine straight playoff games to Montreal since Game 6 of the 1967 Stanley Cup Final, the last time the Maple Leafs won the Cup.
Jesperi Kotkaniemi scored after being a healthy scratch in Game 1, and Carey Price made 29 saves for the Canadiens, the No. 4 seed.
"We were a little better in the third period, but we cut our own legs out with too many penalties in the first and second period," Montreal forward Phillip Danault said. "We had trouble getting back, but we tried the best we could in the third but it was too late."