Josh Adams chipped in 16 points and Riley Grabau added 15 for the Cowboys (15-2, 4-0 Mountain West), who shot 53.7 percent from the field. Nance was 8 of 11 from the field, blocked four shots and dished out four assists.
Derrick Marks finished with 16 points and James Webb III hit 5 of 7 3-pointers to total 15 points for Boise State (10-6, 0-3), which was outrebounded 30-19. No other players had more than seven points as the Broncos lost their fourth straight.
Nance hit a jumper, a pair of layups and two free throws while Adams and Alan Herndon each sank 3-pointers during a 14-7 run that made it 57-47 with 2:39 remaining. Grabau hit eight free throws in the final 1:34.