Zdeno Chara made sure overtime wasn't needed to determine a victor.
The bruising Boston defenseman scored the tiebreaking goal with 1:53 remaining in the third period and the Bruins earned a 4-3 win at Verizon Center for a 2-1 lead in their first-round series with the Washington Capitals.
Chara assisted on two other goals for second-seeded Boston, which got 29 saves from Tim Thomas.
The Bruins traveled to the nation's capital after splitting a pair of low- scoring duels at home. Boston and Washington combined for just four goals in the first two games, with the Bruins winning the opener 1-0 in overtime and the Capitals prevailing 2-1 in double-overtime in Game 2.
Game 4 will be on Thursday in Washington.