Grant also tallied eight assists in the victory and Knight was a sizzling 8-of-10 from the field plus seven rebounds.
The Fighting Irish (16-4, 4-3 Big East) outscored South Florida (10-9, 1-6) by 15 points in the final half and shot 54 percent from the field to 49 percent for the Bulls. South Florida scored just five points in the first six minutes of the second half and lost for the sixth time in their last seven starts.
Zach LeDay led South Florida with 17 points off the bench. Martino Brock and JaVontae Hawkins both added 11.