But instead, Baylor (17-9, 5-8) recovered to win a second straight overtime thriller 70-64 to send a reeling Oklahoma State (16-10, 4-9) to their seventh straight loss in conference play.
After sticking around for a half, Baylor looked to be in trouble in the second half. Only a minute into the half, Oklahoma State pushed their lead to double-digits after jumpers from forward Le'Bryan Nash and guard Phil Forte.
Baylor was unable to overcome OSU's lead until they tied the game up with 5:55 left in the game. A minute later, sophomore center Isaiah Austin slammed an open dunk on the assist by junior forward Royce O'Neale to give Baylor their first lead of the half.
Jefferson nailed a jumper with 1:18 left to give Baylor a 58-55 lead. After a series of missed field goals and free throws, Forte had a shot to tie with 11 seconds left, but he missed and Baylor got the ball out of bounds.
With 3.5 seconds left on the clock, all Baylor had to do was pass the ball in. Unfortunately they were unable to do so, and Hammonds grabbed an ill-advised pass and hit the shot to send the game to overtime.
Many times before, Baylor would have crumbled. But today, Jefferson and a couple of free throws was enough to seal the deal in overtime.
Jefferson scored 25 points, grabbed 13 rebounds and blocked three shots in 40 minutes of action. He shot 8-for-12 from the field, 8-for-11 from the free throw line and made his only three-point attempt.
Austin added 11 points, eight rebounds and two blocks in the second half alone.
Behind a dominant performance from their frontcourt, Baylor outrebounded the Cowboys 51-36. Jefferson and Austin combined for 25 rebounds.
Markel Brown scored 26 points and dished out six assists in the loss. Forte added a quiet 20 points on 5-for-17 from the field.
Baylor shot 37.7 percent from the field and 57.1 percent from the free throw line. They stayed in the game thanks to holding Oklahoma State to 37.3 percent from the field, including 30.6 percent from the field in the second half and overtime.
Baylor will travel to Morgantown to play West Virginia at 12:30 p.m. on Saturday afternoon. The game will be broadcast on the Big 12 Network.