Harris, who went 6-for-12 from the floor and made three 3-pointers, hit a trey with 5 seconds left in the first half to give the Dragons (15-12, 10-5 Colonial Athletic Association) a 35-32 halftime lead.
Drexel maintained control, but the Blue Hens attempted a late rally. Delaware's Jawan Carter scored on a layup with 1:25 to play, cutting the Dragons' lead to 61-58, but Kevin Phillip tipped in a missed jumper by Gerald Colds to give Drexel a five-point cushion.
The Dragons went on to make five of six free throws in the final 35 seconds.
Colds finished with 13 points and three assists for Drexel, which shot 48 percent from the floor for the game.
Carter led Delaware (7-19, 3-12) with 14 points, Alphonso Dawson had 13 points and Jamelle Hagins had 10 points.
