Javan Felix added 16 points and six assists for the Longhorns (23-9), who will face seventh-seeded Baylor in the semifinals on Friday.
Brandon Watkins was the lone double-digit scorer with 10 points for the Mountaineers (17-15).
Texas raced out to a 17-2 start as WVU missed 15 of its first 16 shots from the floor. The Longhorns took a 35-14 cushion into the break and led by as many as 30 over the final 20 minutes.
The Mountaineers shot just 18.2 percent (6-of-33) and missed all eight of their 3-point tries in the first half. WVU finished 30.3 percent (20-of-66) from the field.