Another 3-pointer by M'Baye made it 62-49 midway through the second half before the Mountaineers mounted another charge that came up short.
Oklahoma finished off its fifth straight win at home, never trailing against TCU, Baylor, Iowa State and West Virginia.
The Sooners jumped out to a 10-1 lead and followed that soon after with a string of 12 points in a row, including 3-pointers by Osby and Grooms. Osby's layup in transition bumped Oklahoma's lead to 25-8 with 10:45 left before halftime, and even a 6-minute stretch without a basket didn't put much of a dent in the margin.
Grooms' three-point play restored the lead to 37-20 with 2:24 left in the first half.