Michael Craig registered a double-double with 12 points and 12 rebounds for the Golden Eagles (27-5), who will play the winner of the matchup between Charlotte and Louisiana Tech in the semifinals on Friday.
Julian Washburn paced UTEP (23-10) with 16 points and Vince Hunter scored 14 points.
Both sides went 0-of-9 from 3-point range in the opening period. USM took a 28-24 lead into the intermission after it shot 43.3 percent from the floor before the break. The Miners trailed at halftime despite outscoring USM, 10-2, at the free-throw line in the first half.
UTEP heated up to sink 46.2 percent of its shots from the floor in the second stanza. The Golden Eagles scored 11 points off of turnovers to protect their lead over the final 20 minutes of the contest.
USM finished with a 45-28 advantage in total rebounds.