Kevin Shattenkirk scored the go-ahead goal 56 seconds after the Bruins tied it in the second period, and the NHL-leading Washington Capitals sent Boston to a season-ending 3-1 loss on Saturday that set up a potential first-round playoff matchup between the teams.
Backup Philipp Grubauer made 21 saves for the Capitals. Marcus Johansson and Justin Williams also scored for Washington, which has won 10 of its last 11 games.
Bruins No. 2 goalie Anton Khudobin stopped 21 of 24 shots he faced in the first two periods before he was replaced by starter Tuukka Rask. The team said Khudobin wasn't feeling well. Rask stopped all eight shots he faced in the third period.
Johansson scored on Washington's first shot of the game, four minutes in. Colin Miller tied it for Boston with 15:13 gone in the second, but Shattenkirk put the Capitals back in front less than a minute later. Another Washington goal was waved off for goalie interference, but Williams added one that counted in the final minute of the second period.
Earlier in the day, the Ottawa Senators beat the New York Rangers 3-1 to reach 98 points with one game remaining and eliminate the possibility Boston could finish second in the Atlantic Division. That means the Bruins will start on the road, but they still have a chance to avoid Washington in the first round if they can stay ahead of Toronto.
The Maple Leafs were to host Pittsburgh on Saturday night and Columbus on Sunday. If they get three points out of their last two games, they would pass Boston and finish third in the Atlantic.
Washington had already clinched home ice throughout the playoffs and started Grubauer in place of Braden Holtby.
NOTES: Bruins F Jakob Forsbacka Karlsson made his NHL debut. He's the 10th player to make his NHL debut for the Bruins this season. ... F Brad Marchand missed the second game of his two-game suspension for spearing Tampa Bay defenseman Jake Dotchin in the groin. D Torey Krug, who left Thursday night's game with a leg injury, also did not play. ... Boston D Brandon Carlo left late in the first period after a check by Alex Ovechkin, and did not return. ... New England Patriots quarterback Tom Brady was a luxury suite for the game. ... Washington was without D John Carlson, who missed his third straight game with an unspecified injury, and F Brett Connolly, who was sick.
Capitals: Play Florida on Sunday at 7 p.m.
Bruins: End of regular season. Await the results of Toronto games to find out if they finish third or fourth in the division.