Alex Ovechkin scored his league-leading 31st goal, John Erskine cleared two shots off the goal line, and Braden Holtby made 24 saves for the Capitals, who have won 10 of 11 to secure a playoff berth with two games to spare.
The Capitals were next-to-last in the Eastern Conference as recently as March 21.
ISLANDERS 3 (SO)
In Raleigh, N.C., New York clinched an Eastern Conference playoff spot despite a shootout loss to Carolina.
With the point they received by reaching overtime, coupled with a loss by the Winnipeg Jets at Washington, the Islanders secured a place in the playoffs for the first time since 2007.
Riley Nash and Jeff Skinner scored in the shootout for the Hurricanes.
DEVILS 3, CANADIENS 2
In Newark, N.J., Patrik Elias scored his 375th NHL goal, Martin Brodeur made 19 saves for his 669th victory and New Jersey beat Montreal.
The Canadiens trail Boston by two points in the Northeast with only two games remaining.
PANTHERS 3, RANGERS 2
In Sunrise, Fla., Marcel Goc and Drew Shore scored third-period goals, and Florida prevented New York from clinching an Eastern Conference playoff berth.
BLUES 3, AVALANCHE 1
In St. Louis, Chris Stewart reached career milestones of 100 goals and 100 assists and the Blues clinched a playoff berth.
SABRES 4, PENGUINS 2
In Pittsburgh, Thomas Vanek scored twice, Ryan Miller stopped 40 shots and Buffalo edged the Penguins, snapping the Penguins’ seven-game winning streak.
FLYERS 5, BRUINS 2
In Philadelphia, Matt Read and Oliver Lauridsen scored goals 7 seconds apart to lead the Flyers over Boston.
WILD 2, KINGS 1
In St. Paul, Minn., Charlie Coyle and Cal Clutterbuck scored 16 seconds apart late in the first period, helping Minnesota break its five-game home losing streak and hang on for a critical win over Los Angeles.
The Wild entered the evening in seventh place in the Western Conference.