Petty threw three TD passes, going 17-of-31 for 335 passing yards, and also ran for two more scores as Baylor (9-0, 6-0 Big 12) won a 13th straight to extend a school record.
Levi Norwood lead the Bears' receiving corps with 156 yards on seven grabs -- two of them for touchdowns.
He also returned a punt for a score.
Baker Mayfield made good on 28-of-51 passes for 314 yards with four touchdowns and one interception as the Red Raiders (7-4, 4-4) lost a fourth straight.
Notable deaths of 2014 [PHOTOS]