The Capitals outshot the Panthers 14-9 in the second period and take a 2-1 lead into the third period.
After a goal by the Panthers Stephen Weiss at 4:22 tied the game at 1, the Capitals answered 25 seconds later on a goal by Mike Knuble. Knuble had the puck deflect in off his right skate after Alex Ovechkin attempted to put home the rebound off a Nicklas Backstrom shot.
The big story of the period, though, is the apparent injury to defensman Mike Green. Green took a knee on knee hit from the Panthers Dmitry Kulikov as Green chased a loose puck into the Panthers zone. Green pushed the puck forward, then angled left to avoid an oncoming Kulikov.
Kulikov attempted to turn to finish the hit, but his right knee collided with Green's right knee. Green lay on the ice for several minutes, not moving, and was subsequently helped off the ice by the Capitals' training staff.
The Panthers were awarded a power play as Brendan Morrison was assessed a two-minute minor for roughing as he grabbed Kulikov around the neck after his hit on Green.
Washington killed the first 1:23 of the penalty before Panthers' Captain Bryan McCabe was whistled for roughing Alexander Semin after Semin was stopped on a short-handed breakaway.