I remember the 1998 Alamo Bowl where Kansas State was basically all but guaranteed to win their CCG, so the #2 and #3 affiliated B12 bowls had already made their selections for the next teams down before the game was played. Then KSU lost, and the #4 team in the country got demoted to the 4th-place bowl affiliation to face upstart Purdue (who I think was just barely ranked, around #23 or so).
I believe that KSU team was more talented top-to-bottom than Purdue. I also believe they felt entitled to the win because they were the #4 team and Purdue didn't deserve to be on that field with them. I think they were not mentally ready for a Purdue team led by a gun-slinging Drew Brees and coached by Cowboy Joe that had a chip on their shoulder and something to prove.
Purdue got out to an early lead, and was up 27-13 at the end of the 3rd. In the 4th quarter, I think KSU's talent and depth started to wear, and they had a 21-point 4 quarter, taking the lead and requiring some Brees heroics for Purdue to steal the win.
I really honestly think KSU didn't "come to play" in that game and it took them getting punched in the mouth a few quarters to decide to show up.