Dave Taylor fired in his 29th and 30th goals of the season and Marcel Dionne scored on a short-handed goal for host los Angeles.
The victory, first of the year for Los Angeles over Montreal after three defeats, extended the first-place Kings' lead to nine points over the Canadiens in the Norris Division.
Taylor opened the scoring at 9:11 of the first period on a 15-footer after taking a perfect pass from linemate Charle Simmer, who was credited with three assists.
Dionne made it 2-0 with 8:26 left in the second period when he connected for his 43rd goal of the season on a breakaway while the Kings' Dan Bonar was in the penalty box. Dionne took a pass from Mike Murphy at the blue line and raced in alone to beat Montreal goalie Michel Larocque.
Taylor made it 3-0 with two seconds left in the second period when his linemates Dionne and Simmer set him up with perfect passes before he drilled a 15-footer from the circle.
The Canadiens scored their only goal 18 seconds into the final period on Doug Risebrough's eighth goal of the season. Risebrough was assisted by Rejean Houle.