Taurean Prince added 16 off the bench and Isaiah Austin chipped in 15 as Baylor (11-1) completed a perfect 5-0 mark in December.
Prince and Austin teamed up for 20 of the Bears' first 28 points to help build a 36-25 halftime lead and Jefferson helped seal the win with the first six Baylor points after the break.
Oral Roberts (6-7) was paced by Shawn Glover with 22 points.
Denell Henderson contributed 16 with eight rebounds.
Teacher apologizes for showing sexual image of herself in class
Susan Sarandon 'very excited' about daughter's pregnancy