Dylan Guenther had a goal and an assist, and Schmaltz had two assists for Utah (9-10-3), which had lost four of five. Karel Vejmelka made 11 saves.
Utah, which split its four-game road trip, is 4-3 in overtime, but had lost its previous two overtime games.
“I feel like we stayed calm all game, especially in overtime,” Utah defenseman Maveric Lamoureux said. “Finally, we had some success in overtime, and having ‘Sergey’ score here, I think that was definitely a special moment for him.”
Jayden Struble scored for a second straight game and Sam Montembeault made 26 saves for Montreal (7-12-2), which lost 6-2 against the Vegas Golden Knights on Saturday.
“I think we played a good third period and we could have ended up with the win,” Montembeault said. “But even in overtime, we had possession for a long time there and they scored with like 20 seconds left. It’s unfortunate but we’ve got to move on.”
The Canadiens were outshot 29-13.
“I don’t think the shots were a true reflection of attempts or chances, but it was one of those nights for us,” Montreal forward Alex Newhook said.