Kendall Smith and Cameron McGriff each scored 20 points as the Cowboys (15-10, 5-7) replicated last week's upset win at Kansas.
Jevon Carter snapped out of a mini-slump by scoring 33 points for the Mountaineers (18-7, 7-5), who led by five in the final three minutes.
West Virginia's chance to answer in the final seconds came down to James Bolden's 3-point misfire.
Esa Ahmad added 16 points, including an alley-oop dunk off a lob by Daxter Miles that temporarily gave West Virginia breathing room.
After missing 18 of his previous 25 shots, Carter sank 11 of 18 in the loss. His pull-up jumper put West Virginia up 85-83 with 37 seconds before Waters got free after an Oklahoma State offensive rebound.
Waters finished with 10. Jeffrey Carroll had 14, punctuated by a run-out dunk with one second left.
With McGriff going 13 of 13 at the foul line before fouling out with 3:47 left, the Cowboys made 30 of 36 overall, matching their season high for attempts from the first time they faced West Virginia on Dec. 29.
Ahmad spent most of the first half on the bench after picking up two fouls in the opening 2:29.
Lamont West added 10 points for West Virginia, which had won six of the previous seven meetings.
West sank two 3s during a 14-3 run that gave the Mountaineers a 57-49 edge
On his way to 16 first-half points, McGriff made nine straight free throws, two of which put Oklahoma State ahead 32-27. The lead evaporated over the final 2:47 when Carter countered with nine points to spark a 12-4 run. After his driving step-back jumper with four seconds left made it 39-36, Carter whooped at the Cowboys bench and trotted off to the locker room.
--Field Level Media
Oklahoma State | West Virginia | |
Cameron McGriff 20 | Scoring | Jevon Carter 33 |
Kendall Smith 3 | Assists | Daxter Miles Jr. 5 |
Cameron McGriff 9 | Rebounds | Sagaba Konate 7 |
Cameron McGriff 13 | Free Throws Made | Jevon Carter 10 |
Thomas Dziagwa 2 | Steals | Esa Ahmad 1 |
Yankuba Sima 2 | Blocks | Sagaba Konate 2 |
Team | Points | FG% | 3PM-3PA | FTM-FTA | Assists | Rebounds | Blocks | Steals | Turnovers |
Oklahoma State | 88 | 46.2 | 10-24 | 30-36 | 11 | 31 | 3 | 6 | 13 |
West Virginia | 85 | 51.9 | 5-16 | 24-28 | 13 | 27 | 3 | 4 | 12 |