Mason, Philadelphia's No. 1 goalie who was making his first appearance since Dec. 8, returned to form and earned his first victory in his last eight home starts. Philadelphia has won seven of 10 overall.
The Canucks lost their eighth in 10 games, including the first three of a six-game road trip that continues Friday night at Detroit. Vancouver has been outscored 11-2 in the three road games.
Raffl's tally came on the power play with 3 minutes, 15 seconds left in the first period. Evgeny Medvedev took the initial shot and Raffl's tip got past Jacob Markstrom. However, the officials didn't stop play, thinking the puck hit off the crossbar. Play was halted 22 seconds later and replay officials determined that it was indeed a goal and ordered the arena horn be sounded.
The reverse situation happened just over five minutes into the second period when Claude Giroux's shot on a breakaway was ruled a goal by the on-ice officials, only to be overturned when replays showed it hit off the crossbar.
Couturier finished a rebound after Wayne Simmonds' shot went off the post with 2:50 remaining in the third period to put the game away.
Mason was pulled in his last outing after giving up three goals on 10 shots in a 4-3 overtime loss to the Islanders and watched from the bench as backup Michal Neuvirth started the last three contests.
But Mason was stout against the Canucks, making strong first-period saves on point-blank shots from Radim Vrbata, Chris Higgins and Daniel Sedin. Mason's best save was a highlight-reel glove stop while diving across the crease to deny Alexander Edler on a power-play chance with two minutes left in the second period.
Mason improved to 6-8-4 while earning his second shutout of the season and 28th of his career.
The Canucks did get a shot past Mason when Vrbata fired the puck into the goal from the blue line, but it crossed the goal line just after the second-period horn sounded.
Markstrom had 30 saves while filling in for No. 1 goalie Ryan Miller, who watched one game after being pulled for allowing six goals on 36 shots through two periods in Tuesday's 6-2 loss at Minnesota.
NOTES: Henrik Sedin sustained a lower-body injury in the second period and didn't return. ... The Canucks dropped to 1-7-3 in their last 11 road games. ... The teams ended their regular-season series tied at 1. Vancouver won 4-1 on its home ice Nov. 2. ... Giroux moved into fourth place on the Flyers' list for games played as a captain with his 243rd regular-season appearance with the ''C.''