Harris shot a perfect 7 of 7 before the break and finished 9 of 11 from the field as Fresno State clocked in its seventh win out of the last eight games.
The Bulldogs (15-14, 8-8 Mountain West) jumped out to a 21-point lead at halftime after shooting over 54 percent from the field and 53 percent from 3-point range. The Broncos (18-10, 8-7) shot 25 percent from the floor and 1 of 11 (9.1 percent) from beyond the arc by the break.
Fresno State cooled off slightly in the second half, going over a 5-minute stretch without a basket and finishing at 48.2 percent shooting.
Mikey Thompson led Boise State with 21 points and Nick Duncan added 11 rebounds.