Luke Adam scored twice as the Buffalo Sabres 1, at First Niagara Center.
Jochen Hecht, Jason Pominville and Zack Kassian each scored for the Sabres, who snapped a three-game slide. Jhonas Enroth stopped 26 shots in the win.
Jason Chimera scored the lone goal for the Capitals, who have dropped their past two. Tomas Vokoun was tagged for all five goals on 28 shots.