In 7 of their first 8 games, ISU didn't give up more than 23 points to anyone (lone exception was 35 to UCF). But then Kansas exploded for 45 against ISU. Granted, 1 TD was a late pick-6 by Kansas's defense when there was only about 6 minutes left in the game and ISU was still down 10, but watching the highlights here, Kansas's offense basically had their way with ISU's defense:

https://www.youtube.com/watch?v=gogVDyZV7W8

Kansas's QB had all day to throw, WRs were wide open, and rushing lanes were big enough for cars to drive through.