Pierre Jackson scored 18 points, and No. 13 Baylor 60, on Saturday.
Brady Heslip added 16 points, while Quincey Miller contributed 12 with nine rebounds for the Bears (24-5, 11-5 Big 12), who won their second straight and three of their last four.
Steven Pledger paced all scorers with 21 points, and Romero Osby and Cameron Clark each netted 12 for the Sooners (14-14, 4-12), who have lost seven of eight.
Baylor shot just 38.9 percent (21-of-54) from the field, but held Oklahoma to 39 percent (23-of-59) and prevented the Sooners from sinking a three-pointer (0-for-12). The Bears shot 34.8 percent (8-of-23) from three-point range.
Osby's jumper with 10:59 remaining in the second half tied the game at 46. It was the 12th tie of the contest and sixth of the half, and also the last.
Jackson drained a three-pointer on the next trip to spark a 13-2 Baylor run, capped off by two treys from Heslip that gave the Bears a 59-48 advantage with 5:43 to play.
"We just had a hard time getting our offense into play. We just had to slow down, and the second half we came out and we were more focused and executed more," said Jackson.
The Sooners would get no closer than seven before the buzzer sounded.
I think the second half we didn't shoot quite as well, largely in part of [Baylor's] length and ranginess," said Oklahoma head coach Lon Kruger. "We missed some opportunities and they knocked down shots to make an even ball game, then eight to 10, and we were fighting from that deficit the rest of the way."
Baylor never led by more than two in the first half, as Oklahoma kept the game close, forcing six ties in the period. The Sooners held a 34-31 edge at the break.
Oklahoma's failure to convert a three-point attempt ended a streak of 510 consecutive games with a trey...There were six lead changes...Andrew Fitzgerald had nine points and nine rebounds for Oklahoma.