After Canadiens' defenseman Andrei Markov shot the puck wide in the top half of the sixth round, Bailey came down the ice with speed on his attempt and buried a wrister past the stick side of Peter Budaj for the winner.
Bailey added an assist in regulation, while Mark Streit and Frans Nielsen scored for the Islanders, who snapped a five-game slide. Al Montoya made 28 saves in the victory.
Aaron Palushaj and Louis LeBlanc lit the lamp for the Canadiens, who have lost three of their last four games. Budaj stopped 36-of-38 shots in defeat.