Utah State (21-9, 11-7 Western Athletic) got 14 points each from Spencer Butterfield and TeNale Roland. Both men hit three 3-pointers. Jared Shaw scored 11 points.
Utah State also had a big 42-26 rebounding advantage, with Marvin Jean getting 10 and Shaw getting nine.
Utah State had a 22-6 scoring edge off the bench.
UTSA (8-21, 3-14) struggled with its shooting, hitting just 19 of 58 for 32.8 percent.
Michael Hale III led UTSA with 21 points, including four 3-pointers. Jeromie Hill had 10 points and Kannon Burrage had nine rebounds.