Johnny Gaudreau scored late in the third period to complete the rout.
Almost eight minutes into the game, three Canadiens forwards were caught up the ice and Mark Giordano, as the trailer, converted a Matthew Tkachuk pass into the first Flames goal.
A turnover by heretofore steady Jordie Benn resulted in a Michael Stone goal 8:36 into the second period, stretching the home team’s lead to 2-0.
Seven minutes later, Sean Monahan and Micheal Ferland scored within 26 seconds to turn the game into a 4-0 rout.
Shots were 37-23 for the home team.