Pittsburgh Penguins defenseman Matt Niskanen (2) puts the puck behind Washington Capitals goalie Braden Holtby (70) and Washington Capitals defenseman Karl Alzner (27) for a game-winning goal in the third-period goal of an NHL hockey game in Pittsburgh Tuesday, March 19, 2013. The Penguins won 2-1. (AP Photo/Gene J. Puskar)

Photo by: Gene J. Puskar

Pittsburgh Penguins defenseman Matt Niskanen (2) puts the puck behind Washington Capitals goalie Braden Holtby (70) and Washington Capitals defenseman Karl Alzner (27) for a game-winning goal in the third-period goal of an NHL hockey game in Pittsburgh Tuesday, March 19, 2013. The Penguins won 2-1. (AP Photo/Gene J. Puskar)