BOSTON (AP) Alex Chiasson had already scored once when he blocked a shot on the penalty kill, gave the puck a little kick and went off toward center ice.
Crossing the red line with three Bruins in pursuit, the Capitals forward moved in on Anton Khudobin, went to his backhand and beat the Boston goalie on the stick side. His two third-period goals made it 4-1 and sent Washington on its way to a 5-3 victory on Thursday night.
''The short-handed goal was massive,'' Washington coach Barry Trotz said. ''If they score one there, the last few minutes would have been hectic.''
Patrice Bergeron scored his 265th career goal to move past Bobby Orr on the Bruins all-time list, and then added another in the final seconds. Bergeron is 11 goals behind Wayne Cashman for seventh in franchise history.
''I love my old Bruins - Bobby Orr, the most,'' Boston coach Bruce Cassidy said. ''But good for Pat. The more he scores, the more it helps us win.''
Braden Holtby stopped 33 shots for the Capitals, who have beaten Boston 11 straight times. Jakub Vrana and Nicklas Backstrom also scored for Washington, and Alex Ovechkin added an empty netter after Boston cut the deficit to two goals with 4 minutes left.
David Krejci also scored for Boston, and Khudobin made 16 saves.
Backstrom gave Washington the lead midway through the second, and Chiasson added to it with 12 minutes left in the game when he took two swipes at a puck in the crease to get it past Khudobin. But an interference penalty on Brooks Orpik gave the Bruins hope to again make it a one-goal game.
Instead, Chiasson extended the lead to 4-1.
''It's always a little special for me to come here,'' said Chiasson, who went to Boston University. ''It was three of the best years of my life, so far.''
Vrana cut through two Boston defenders to give the Capitals a 1-0 lead after one period. Bergeron tied it on a power play in the second, getting the shot off just as Chiasson was knocking his leg out from under him.
The Bruins had won three straight and nine of 11. Washington has won six of seven and nine of 11.
NOTES: Orr also scored six goals in 26 games with the Chicago Blackhawks. ... The Bruins placed F Matt Beleskey on waivers for the purpose of assigning him to Providence of the AHL. He had appeared in 14 games for Boston this season. ... Marchand got his 400th career NHL point. ... Washington F Brett Connolly played in his 300th game. ... The Bruins haven't beaten the Capitals since March 9, 2014. ... David Pastrnak, who assisted on Krejci's goal, has a point in 10 straight games.
Capitals: Host Anaheim on Saturday.
Bruins: Host the New York Rangers on Saturday.
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