Thanks to three of the NHL's oldest players, the Maple Leafs inched within a point of the Bruins for first place in the Northeast Division.
Belfour recorded his 73rd career shutout -- one behind New Jersey's Martin Brodeur for the most among active goaltenders -- and eighth this season. Recently bothered by a bad back, the 38-year-old stopped 27 shots over the final 40 minutes.
Nieuwendyk, 37, opened the scoring 58 seconds into the second period and Francis, 41, made it 2-0 less than eight minutes later. It was Francis' first goal since he was acquired from Carolina at the March 9 trade deadline.
Nik Antropov added an empty-netter for the Leafs, who were coming off Tuesday's embarrassing 7-2 home loss to Tampa Bay.