Carlson, who extended his point streak to four games (one goal, six assists), has 30 points (eight goals, 22 assists) in 20 games. It's the eighth time in NHL history a defenseman has needed 20 games or fewer to reach 30 points, first since Al MacInnis for the Calgary Flames in 1990-91.
The Capitals outshot the Flyers 16-5 in the first period, but Hart kept Philadelphia in the game.
"He played a great game obviously," Giroux said. "Trying to play better in front of him. That's a good hockey team on the other side, but I think in the second and third we played the way we wanted to."
Giroux tied it 1-1 at 6:38 with a power-play goal set up by Voracek cutting through the Washington zone.