Bell sank 9-of-18 shots, including four 3-pointers, as the Wildcats (17-2, 6-1 Big East) never trailed in bouncing back from a 96-68 drubbing at the hands of Creighton Monday.
The Warriors tied the game 77-77 on three straight free throws by Todd Mayo in the closing seconds and game went into overtime when a Tony Chennault basket before the buzzer was waved off on a controversial charging call.
But in the extra time, Villanova went ahead 82-77 on a three-point play by JayVaughn Pinkston and cruised from there.
Ryan Arcidiacono (20 points, 11 assists), Darrun Hilliard II (20 points) and Pinkston (12, eight rebounds) each played big roles for the Wildcats.
Marquette (11-9, 3-4) was led by Davante Gardner with 29 points and 13 rebounds.
Todd Mayo supplied 18 points off the bench.