Jake Evans scored, and Charlie Lindgren made 28 saves for the Canadiens (31-30-9), who are eight points out of wild-card position.
"When you get some good chances, you need to bear down," Evans said. "That's what they did tonight. I feel like the game was pretty even for the most part. When they had their good chances, they were putting them in."
Driedger, who had not played an NHL game since Oct. 28, 2016 coming into the season, is 6-2-1 with a 2.16 goals-against average and a .936 save percentage. He stopped Max Domi on a breakaway at 4:37 of the second period to keep the score 0-0.
"You don't really have time to think about the logistics at that point," Driedger said. "Anyone in this league has done the preparation already, you just go out there and play. I think he was trying to cut back there, and I just sort of read that he was going to cut back. He ended up stuffing it into my stick there."
Wallmark scored at 10:22 of the second period when he came in alone on Lindgren after Noel Acciari's backhand deflection of Aaron Ekblad's outlet pass. His short backhand made it 1-0; it was his second goal since Jan. 10 (22 games).
"It means a lot, and it was a big goal for us too," Wallmark said. "It's nice to get that one out of the way. I felt a had a little speed there and could challenge him a little bit (with the backhand). It was a great pass right on my tape and it was nice to see the puck go in."
Florida killed a four-minute penalty later in the period, including 1:10 at 5-on-3.
"I don't know if it was the turning point, but we could have done a much better job," Montreal coach Claude Julien said. "Five-on-3, for some reason we were shooting from far out. We weren't taking the time to bring the puck a little closer to the net and create some better chances. We still had lots of time. It would have been good to score on that. It would have made probably a difference in the game."
Weegar made it 2-0 41 seconds into the third period with a one-timer from the point right after the Canadiens killed a penalty. Jonathan Huberdeau made it 3-0 at 4:13 when he redirected Erik Haula's centering pass from the boards. Evans scored at 8:04 to make it 3-1, and Mike Hoffman scored an empty-net goal with 1:54 left for the 4-1 final.
The Panthers retired the No. 1 jersey of goalie Roberto Luongo, the first player honored by Florida, prior to the game.
"There was a lot of talk to 'Do it for [Luongo]' in here," Panthers defenseman Aaron Ekblad said. "Obviously, [Driedger] had a great game, some guys scored some big goals and we had some huge blocks on that 5-on-3. It's something we can rally behind for the rest of the year."
