WASHINGTON -- With one team battling for a playoff spot and the other angling for home ice in the first round, the Washington Capitals steamrolled Boston 3-0 on Wednesday night in what could be a damaging blow to the Bruins' hopes of an eighth straight postseason appearance.

Capitals defensemen John Carlson and Matt Niskanen and left winger Marcus Johansson each scored goals and Braden Holtby turned aside 27 shots to become the first goaltender to shut out the Bruins in a season series.

With the win, the Capitals (45-25-11, 101 points) moved three points ahead of the third-place New York Islanders in the Metropolitan Division standings. The Caps can clinch home ice with any combination of a point gained against the New York Rangers in their season finale on Saturday or a point lost by the Islanders in their final two games against the Pittsburgh Penguins and the Columbus Blue Jackets.

The Bruins' predicament became a lot more dire with their loss. Boston (41-26-13, 95 points) is tied with the Ottawa Senators for the final wild-card spot in the Eastern Conference. Both teams have 95 points with two games to play.

The Bruins close out the regular season with road games against the Florida Panthers on Thursday and the Tampa Bay Lightning on Saturday. The Senators finish with road games against the Rangers and the Philadelphia Flyers.

The Bruins own the first tiebreaker, with two more regulation or overtime wins.

With his 28-save shutout, Holtby became the 10th goaltender to shut out the Bruins three times in one season and the first to do it since former Montreal Canadiens netminder Cristobal Huet in 2005-06.

The Capitals, who rank third in the NHL in points by defensemen, grabbed a 2-0 lead in the first period on goals from Carlson and Niskanen.

Carlson gave the Caps a 1-0 lead 4:49 into the game when he blasted a pass from center Nicklas Backstrom past goaltender Tuukka Rask's glove for his 12th goal of the season.

Niskanen made it 2-0 on Washington's next shot, hammering another Backstrom pass off the stick of Boston defenseman Zach Trotman and behind Rask (30 saves) for his fourth goal of the season.

Holtby was tested in the second period, when he stopped Bruins left winger Loui Eriksson on a two-on-one about six minutes into the period, then closed his pads to make a save on left winger Milan Lucic's breakaway.

The Caps completed the scoring with 2:13 remaining in the second period when Johansson finished a beautiful feed from behind the net from rookie center Evgeny Kuznetsov for his career-high 20th goal of the season.

NOTES: D Dougie Hamilton (ribs) did not make the three-game trip with the Bruins but could be cleared before the start of the playoffs if Boston gets there. The Capitals were without C Eric Fehr (upper body), C Jay Beagle (shoulder) and RW Tom Wilson (head), but all three are expected to be back for the playoffs. Because of the injuries, 23-year-old RW Stanislav Galiev made his NHL debut for the Capitals and played on an all-rookie fourth line with LW Andre Burakovsky and C Michael Latta. ... Bruins G Tuukka Rask tied a franchise record owned by Byron Dafoe (1998-99) with his 68th appearance of the season. Capitals G Braden Holtby played in his 72nd game of the season, one short of the franchise record set by Olie Kolzig in 1999-2000. ... The Bruins conclude their season-ending, three-game trip with games against the Florida Panthers on Thursday night and the Tampa Bay Lightning on Saturday. The Capitals close their regular season on Saturday afternoon at home against the New York Rangers.