Bell finished with 249 passing yards and the two TDs on 14-of-22 passing while Saunders made six catches for 153 yards, and the Sooners (7-1, 4-1 Big 12) notched a seventh straight home win.
Damien Williams carried the ball 19 times for 97 yards and two touchdowns for Oklahoma.
The Red Raiders (7-1, 4-1) fell for the first team this season despite 385 passing yards and two touchdowns from Davis Webb. He connected on 33-of-53 pass attempts but was picked off twice.
Eric Ward corralled both of Webb's scoring strikes, finishing with nine catches for 106 yards.