Tippett tied it 3-3 at 15:50, shooting directly off a face-off in the right circle.
"It's not very often you get it clean like that, and I think it just caught (Allen) a bit," Tippett said.
Kevin Hayes put Philadelphia back in front 4-3 at 8:17 of the third period with a quick shot from above the left circle after Nick Seeler's initial chance was blocked.
"I thought we did some good things," Hayes said. "I thought our team worked very hard tonight, but it's tough when you lose a couple of games in a row and then they score with one second left. It's easy to say things aren't going our way, but we've just got to keep working hard, and things turn."
NOTES: Hayes has six points (three goals, three assists) during a five-game point streak. … Laughton had to be helped off the ice at 1:47 of the third after he was checked into the boards by Montreal defenseman Kaiden Guhle. Tortorella did not have an update postgame. … The Flyers played without forward Travis Konecny, who returned to Philadelphia after he sustained an upper-body injury during a 4-1 loss at the Boston Bruins on Thursday. … Matheson is the fifth defenseman to score in his Canadiens debut, joining Scott Lachance (March 11, 1999), Jyrki Lumme (Nov. 26, 1988), Bill MacKenzie (Dec. 5, 1936) and Howard McNamara (Dec. 24, 1919).