Askia Booker scored 14 points and Carlon Brown had 10 points for the Buffaloes (4-2), who extended their non-conference home win streak to 26.
Kentavious Caldwell-Pope scored 15 points and Gerald Robinson 14 for the Bulldogs (4-3), who have lost three of their last four.
Colorado came out aggressive to start the second half, hitting five of their first six shots to take a 45-39 lead with 15:57 remaining.
Roberson converted a three-point play, Nate Tomlinson hit a 3-pointer and Shane Harris-Tunks made a layup to give the Buffaloes a 62-52 lead with 3:52 left.
The Bulldogs rallied late to cut the lead to three with 4.5 seconds left, but a free throw by Booker sealed the win.