Garon stopped all 13 shots he saw over the final two periods for the Lightning, who won for the fifth time in seven games and remained five points out of the eighth and final playoff spot in the Eastern Conference.
The listless Canadiens, meanwhile, dropped their fifth straight contest.
David Desharnais scored Carey Price made 20 saves for the Habs.
Reindeer recovered after escaping from Santa during lighting ceremony
N.J. man wakes up from 10-hour sleep with knife in back