The Cowboys stayed close in the second half. Markel Brown made a 3-point jumper with 11 seconds remaining to pull OSU to within 2 points at 62-60.
But that was the closest the Cowboys would get as Anthony Jones made a pair of foul shots to secure the victory for Baylor (21-2, 8-2 Big 12).
Quincy Acy added 11 points and 12 rebounds as the Bears won a fourth straight following their only losses of the season.
The Cowboys (11-12, 4-6) got a game-high 23 points from Brian Williams in the loss.