The win was Dayton's seventh straight to go 3-0 to start the conference season.
The Flyers shot 60.5 percent, knocking down 26 of 43 shots from the field, including 7 of 16 from long range, and were 17 of 20 from the line. Fordham, meanwhile, was just 20 of 60 (33.3 percent) from the floor.
Dyshawn Pierre scored six points and Darrell Davis knocked down a pair of 3-pointers in a 14-4 run to push Dayton's lead to 54-43 with under seven minutes to play.
Pierre finished with 16 points to lead Dayton, with Smith adding another 15 and Jordan Sibert 14.