Cameron Clark scored 14 and Jordan Woodard contributed 10 points and eight assists for the Sooners (14-4, 3-2 Big-12).
Woodard's free throw with 9.1 seconds remaining gave Oklahoma a two-point lead, and the Sooners held on for the win when Royce O'Neale's jumper from the left wing came too late to the beat the buzzer.
Baylor (13-4, 1-3) got 16 points from Kenny Chery in its first home loss of the season.
Isaiah Austin netted 12 points and Cory Jefferson added 11 for the Bears.
Notable deaths of 2014 [PHOTOS]