Ovechkin sat out Wednesday's loss to Ottawa with a lower-body injury he had suffered two nights earlier in a setback against Carolina.
The Capitals ended a three-game skid and moved within a point of Florida for the eighth playoff spot in the Eastern Conference.
Mathieu Perreault opened the scoring for Washington 6:58 into the contest and the Capitals took a 3-0 advantage when Jason Chimera and Ovechkin scored 16 seconds apart in the middle period.
Montreal suffered its third straight loss. Carey Price gave up three goals on 23 shots.
Notable deaths of 2014 [PHOTOS]