The Capitals maintain a narrow lead in the Metropolitan Division, leading the New York Islanders by one point and the Pittsburgh Penguins by three. Each team has six games remaining, with Washington hosting the Islanders in the regular-season finale on April 6.
The Capitals snapped a two-game losing streak and completed a sweep of their four-game season series with the Flyers, whose fading playoff chances took a hit.
Braden Holtby played another strong game for Washington with 35 saves. Alex Ovechkin did not score a goal for the eighth time in his last nine games, but tallied one assist.
Andrei Svechnikov scored 3:15 into overtime as Carolina defeated visiting Montreal at Raleigh, N.C.
Svechnikov scored his 20th goal of the season, this one set up on an assist from Jordan Staal. It was Carolina's only shot in overtime.
Trevor van Riemsdyk scored the tying goal in the third period for Carolina, which won four of five games during a homestand. Hurricanes goalie Curtis McElhinney stopped 28 shots, and Montreal goalie Carey Price made 38 saves.
Jordan Eberle scored early in the first period and Robin Lehner recorded his fifth shutout of the season with 31 saves as New York further damaged the playoff hopes of visiting Arizona with a win in Uniondale, N.Y.
Brock Nelson scored on a wraparound with 3:14 left in the third for the Islanders (44-25-7, 95 points), who won for the second time in as many days to remain in second place in the Metropolitan Division.
Goalie Darcy Kuemper, who made his 17th straight start, made 24 saves for the Coyotes (36-33-7, 79 points), who lost their fifth straight (0-3-2) and missed another chance to move into the final wild-card spot in the Western Conference.
Duncan Keith scored the game-winning goal 1:23 into overtime to carry host Chicago to a win over Colorado to keep his team's slim playoff hopes alive.
The 35-year-old Keith denied Nathan MacKinnon on a one-on-one battle, then raced the length of the ice and slid in the game-winner for his sixth goal of the season. Both goaltenders -- Chicago's Corey Crawford and Colorado's Philipp Grubauer -- played back-to-back games for just the second time this season. Crawford made 19 saves, Grubauer 40.
The win pushed Chicago to 76 points in the standings -- five behind Colorado, which holds the Western Conference's second wild card, and three behind the Minnesota Wild and Arizona Coyotes.