Drummond hit four free throws for Toledo (8-0) in the game's final minute, including two with 25 seconds remaining to extend the Rockets' lead to 80-77.
Drummond committed a foul with 1 second remaining, sending Robert Morris to the free throw line trailing by three. Karvel Anderson missed the front-end of the one-and-one and Toledo held on for the win.
Robert Morris shot 73.9 percent (17-for-23) from the field in the first half but led just 41-37 at halftime. The Colonials shot 63.3 percent for the game. Lucky Jones scored 25 for Robert Morris and Anderson added 23.