Craig Smith scored his first two goals since being acquired on Feb. 23, and Darcy Kuemper made 38 saves for the Capitals (31-27-6), who have won three of four after losing six straight.
Washington is three points behind the Pittsburgh Penguins, who have played two fewer games, for the second wild card into the Stanley Cup Playoffs from the Eastern Conference.
"I thought the guys that jumped in had a really nice game," Capitals coach Peter Laviolette said. "I think the response after the first period, guys came out and played a much better brand of hockey and dug in and chipped away at it and were able to score some goals in the second and get some life after that."