Sanders also had a career-best 23 points on 7-for-12 shooting and Chad Sherwood added 19 points, hitting 7 of 10 from the floor and 4 of 6 from long range.
Idaho (2-1) took the lead for good at 16-13 early in the first half on Jordan Scott's 3-pointer and carried a double-digit advantage into the break. The Vandals continued to pull away in the second half, outscoring Linfield 44-28 over the final 20 minutes.
Linfield, a Division III program, was led by Kyle Maloof, who scored 10 points.
The game marked the first of the new season for Arkadiy Mkrtychyan, the Vandals' leading returning scorer and rebounder. Mkrtychyan missed the first two games because of a training camp injury. He scored six points.