Philadelphia won its seventh straight after hearing that team captain Chris Pronger would be lost for the rest of the season due to a concussion.
The Flyers never trailed, but during the first two periods each of Philadelphia's three goals was answered by one from the Canadiens.
Montreal could not respond, however, to a slap shot from Meszaros that eluded Carey Price 8:08 into the final period. The Canadiens had won their previous two games.
Sergei Bobrovsky got the win by stopping 28-of-31 shots. Philadelphia moved two points in front of idle Boston for the best record in the Eastern Conference.
Price made 25 saves and suffered his first loss since Nov. 25.
Swim Week Miami Beach 2014 [PHOTOS]