Braden Holtby made 29 saves for the Capitals.
The game was physical and scoreless until Thomas turned back a Washington attack early in the extra period. Brian Rolston dropped it for Benoit Pouliot to clear the zone and he pushed it up to Kelly, who slapped it over Holtby’s glove for the game-winner.
The reigning Vezina and Conn Smythe Trophy-winner, Thomas had an easy game for much of the night, including a middle period in which Washington managed just two shots on goal.
STOPPED COLD: Tim Thomas makes a save during the Bruins’ 1-0 overtime win over the Capitals last night in Boston.
Blues 3, Sharks 2 ( 2 OT)
In St. Louis, Martin Havlat scored his second goal of the game 3:34 into the second overtime as San Jose beat the Blues in Game 1 of their playoff series.
Andrew Desjardins tied it for San Jose with 5:16 in regulation, banging in a one-timer from the slot from Tommy Wingels, and Dan Boyle had two assists. Antti Niemmi made 40 saves.
Coyotes 3, B’hawks 2 (OT)
Martin Hanzal scored 9:29 into overtime as Phoenix won Game 1 of their playoff series.
Despite losing leading goal scorer Radim Vrbata to an injury early, Phoenix had a 2-1 lead after Taylor Pyatt and Antoine Vermette scored in the second period. Jonathan Toews scored for Chicago in his first game back from a concussion.
Capitals, Stanley Cup champion Bruins, Thomas, Tim Thomas, Benoit Pouliot, Martin Havlat, Conn Smythe Trophy-winner, Brian Rolston, Chris Kelly, overtime, Boston, Martin Hanzal, Tommy Wingels, Washington, Antoine Vermette