Mikael Backlund, with two, and Andrew Mangiapane replied for Calgary (16-21-3). Jacob Markstrom stopped 25 shots for the Flames, who have lost four straight and eight of their last nine in regulation. Elias Lindholm had two assists.
Currently the Leafs' No. 1 option with Frederik Andersen still dealing with a lower-body injury, Campbell's win streak equals a Leafs' record shared by Felix Potvin (1993-94), Jacques Plante (1970-71) and John Ross Roach (1924-25).
North Division-topping Toronto, which swept a four-game road trip through Winnipeg and Calgary, leads the second-place Jets by six points in the standings, while the Edmonton Oilers are seven back in third.