With 1:53 left in regulation and the score tied 3-3, Patrice Bergeron got the puck and fed it to Chara on the right wing, who one-timed a shot at Washington goalie Braden Holtby.
The shot deflected off the stick of Capitals defenseman Roman Hamrlik and got past Holtby, handing the Bruins a victory and a 2-games-to-1 lead in their Eastern Conference quarterfinals series.
Tim Thomas earned the victory by stopping 29-of-32 shots.
Holtby finished with 25 saves.
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