Jason Chimera and Mike Knuble each registered a goal and an assist for the Caps, who maintained their two-point lead over Buffalo in the competition for the eighth and final Eastern Conference postseason berth.
The Sabres routed Tampa Bay 7-3 Monday.
Braden Holtby turned aside 30 shots for the Capitals, who also pulled to within three points of Florida atop the Southeast Division with the victory.
The Red Wings fell to 0-4-1 in their last five games but remained tied with Nashville for the fourth spot in the West.
Ohio bar shooting arrested, charged with murder
Duggar sisters unveil Christian dating rules in new book