Ryan Poehling had a goal and an assist for the Flyers (28-34-8), who are 1-8-0 in their past nine, and had been shut out in two straight, including 2-0 at Tampa Bay on Monday. Ersson made 13 saves.
“Another good team that we played a pretty good game against,” forward Travis Konecny said. “Obviously some mistakes that we could clean up. We’ve been playing well against good teams for the most part and got to keep on going.”
Duhaime increased the Capitals' lead to 2-0 at 1:56 of the second period when he deflected Matt Roy’s shot past Ersson.
“Struggled a little bit in the second,” Flyers coach John Tortorella said. “I thought we were sloppy with the puck. Kept plugging away.”
Mangiapane, who wears No. 88, made it 3-0 at 11:06 when he converted a pass across the slot from Beauvillier on a 2-on-1 rush.
"It was pretty fun there,” Mangiapane said. “I saw up on the banner there or whatever it was 888, so I said, 'Maybe it's a good sign for me and maybe I'll get one here.' It worked out pretty well and just kind of manifested it there.”