Stephen DuCharme also had 11 points for USU (13-5, 2-2 Western Athletic Conference).
The teams attempted a combined 48 3-point shots in the game, 33 of them by Idaho. Many of the Vandal misses led to fast-break baskets for USU, who scored 16 points on layups and short-range jumpers in the second half.
USU also outrebounded Idaho 21-13 in the second half.
In the first half, the teams traded baskets until a 16-17 Vandal lead at the 9:30 mark. USU then went on a 14-4 run, keyed by three 3-point baskets by reserve Hammer.
Idaho stayed close in the first half thanks to 19 points on 6-for-10 shooting from the field by Watson, but USU led 42-34 at halftime.