Kansas surrendered a safety on its first play from scrimmage and things only got worse.
Kansas State (7-2, 3-2 Big 12 North) moved the ball at will in the annual meeting for the Governor's Cup, defeating the Jayhawks for the 10th straight time.
About the only time the Wildcats stalled in the first half was on the first possession of the game, when Kansas State was forced to punt and the kick by Travis Brown was downed at the Kansas one.
Clark Green was tackled in the end zone on the next play for a safety.
Following the free kick, Roberson completed a 40-yard pass to Taco Wallace, setting up a four-yard scoring run by Roberson.
Darren Sproles scored on an eight-yard run and Roberson tossed a 19-yard touchdown pass to James Terry, increasing the lead to 23-0.
A four-yard touchdown run by Roberson increased the lead to 30-0 after one quarter.
Joe Rheem kicked field goals of 37 and 28 yards and Roberson scored on a one-yard run, extending the halftime cushion to 43-0. The loss continued a dismal first season for Kansas Coach Mark Mangino, an assistant at Kansas State under coach Bill Snyder from 1991 to 1998.
The only wins for Kansas (2-8, 0-6 Big 12 South) this season have come against Tulsa and Division I-AA Southwest Missouri State.
The Wildcats added to their lead with touchdown runs of 26 yards by Sproles, two yards by Ayo Saba and four yards by Marc Dunn.