Vancouver was down 0-2 before the third and final period when Elias Pettersson reduced with his first goal of the season.
The Swedish star, in position in the castle, steered in a shot from Jordie Benn.
Shortly afterwards, Nils Höglander equalized from an almost identical position in the castle when he whipped in a backhand to 2-2.
Visiting Montreal, however, managed to recover and eventually won 5-2.
For the team's goalkeeper Carey Price, who saved 23 shots, it was victory number 350 in his NHL career.
FROM YESTERDAY: Here Landeskog becomes a hero in a sudden - despite giant rescue
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Gabriel Landeskog put the decisive 3-2 in overtime against Anaheim.
Photo: Viaplay / TT