With Purdue leading, 17-7, in the third quarter of last Saturday's game at Iowa, the Boilermakers were driving for another touchdown.

That's when it happened. That's when a seldom invoked penalty was applied: The dreaded fumble out of the end zone that results in a touchback.

Here's the setup: On 3rd-and-goal from the Iowa 6-yard line, Purdue quarterback Aidan O'Connell hit wideout TJ Sheffield with a short pass. Sheffield raced toward the south end zone of Kinnick Stadium.