Philadelphia had scored three straight goals — including two in the third period — to erase a two-goal deficit.
John Carlson and Joel Ward both scored from point-blank range on Philadelphia's Ray Emery in the second period to give the Capitals a 2-0 edge. Emery finished with 29 saves on 32 shots.
Jakub Voracek started the Flyers' comeback, taking a pass from Jason Akeson and scoring on David Leggio to make it 2-1 in the final minute of the second period. Vincent Lecavalier tied it with a power-play goal 1:53 into the third, and Akeson put Philadelphia in front at 6:09.
Leggio stopped 14 of 17 shots in relief of Michal Neuvirth, who turned aside all 16 shots he faced.
He's only 17 but he can see the ice so well and he moves the puck and goes to the open ice all the time, so I just think he's a player that is ready to play in the NHL. I'm really looking forward to coaching someone like this.
— U.S. National Junior Team coach Ron Wilson on Auston Matthews, the projected No. 1 pick of the 2016 NHL Draft