Gielo also pulled down 10 rebounds for Liberty (2-0) in a game that was tied 30-30 at halftime and saw eight ties and nine lead changes.
Cazmon Hayes topped the Blue Hens with 17 points. Delaware hit just 30 percent of its field goals (20-67) but owned the boards, 47-37, and outscored Liberty 22-16 in the paint.
A jumper by James Johnson (nine points) and a 3-pointer by Gielo spurred Liberty to a 35-30 lead to start the second half, but the Blue Hens soon edged ahead 38-37 on an Eric Carter dunk. The teams traded a one-point lead until Gielo hit another 3 to spark a 10-0 run.
Barnett Harris (two points) dunked for Delaware's last lead with 3:03 left.