The Sooners (10-6, 1-1 Big 12) took advantage of the absence of Big 12 scoring leader James Anderson due to an injury to surge ahead in the second half, then closed out the victory in overtime after squandering a five-point lead in the final 20 seconds of regulation.
Tommy Mason-Griffin put Oklahoma ahead with a 3-pointer with just under 3 minutes left in overtime, and Warren sealed the win by hitting two free throws with 10.7 seconds to play.
Anderson led Oklahoma State (13-3, 1-1) with 18 points but was ineffective after returning from a head injury in the second half. Marshall Moses added 16 points and 13 rebounds and freshman Ray Penn scored 14 points for the Cowboys.
The Sooners scored 13 straight points to surge into the lead after Anderson went out of the game with about 13 minutes left to play and appeared to get stitches on the side of his head at the end of the Cowboys' bench.
By the time he returned, Oklahoma State's eight-point lead was gone and the struggling Sooners found a way to close out their sixth straight win in the series on their home floor.
Oklahoma was coming off its most lopsided loss in 28 years -- since the program's last losing season -- and appeared in trouble before Anderson got hurt.
He remained on the floor under the basket for a few moments as trainers attended to him, and he then walked to the end of the Cowboys' bench with a towel pressed up against the side of his head. A trainer appeared to give Anderson stitches as play continued and Oklahoma charged back from a 42-34 deficit.
Tony Crocker, Mason-Griffin and Steven Pledger hit consecutive 3-pointers to push Oklahoma into the lead at 43-42 before Anderson returned with 8:07 to play. Crocker extended the Sooners' lead with a layup before Anderson touched the ball for the first time, fumbling away his dribble against Warren before getting it back with a dive. He then picked up two fouls in a 24-second span, with Warren blowing past him for a layup in between to make it 47-42 Sooners with 6:35 left.
Penn stopped Oklahoma State's dry spell and cut the deficit to three with a driving layup, but it was the team's only basket in a 12-minute span after Anderson went out.
Penn connected again on a 3-pointer from the left wing with 17.4 seconds left, then Anderson put back his own missed layup with 3.7 seconds left after freshman Mason-Griffin missed a pair of free throws that could have iced the game.
Mason-Griffin finished with 14 points for the Sooners, who shot only 38 percent but were still 10 percentage points better than Oklahoma State, which was 19-for-69.