With Max Talbot in the box for holding and the Capitals on the power play, Mike Green stepped into the slot and fell. The loose puck bobbled around in front of the net where Mike Knuble found it and poked it past Penguins goaltender Marc-Andre Fleury.
It's Knuble's ninth goal of the season and it tied up the 2011 Winter Classic at 1-1 with about 14 minutes left in the second period. Assists went to Nicklas Backstrom and Green.
Video of the goal:
The Capitals seem to be rolling now, getting sustained pressure in the Pittsburgh end for several shifts following the goal.