PSU didn't seem to be quite ready for the speed of Michigan's hurry-up offense on the game's opening drive, and rookie quarterback Tate Forcier led his squad straight down the field.
After a swing pass from Forcier to tailback Martavious Odoms took the Wolverines from the Penn State 22 down to the 2, the Lions scrambled to get their goal-line defense on the field.
In the heat of the moment, one defender who is usually a part of the goal-line unit went to the sideline instead of remaining on the field
It was a rare error for a unit that has been spectacular all season, leading the Big Ten in scoring defense by allowing less than nine points per game.
True to form, despite being a man down — and even though Forcier appeared to spot the shortage and ran a play at what should have been a soft spot in the defense — the Lions rose to the occasion and came up with a stop.
On the next play — against 11 men — Michigan punched in the only first-half TD Penn State has allowed this year. But that was beside the point.
They key here is that, even when outnumbered, the Penn State defense is pretty good. And it proved it by only allowing a field goal the rest of the way in a 35-10 win over Michigan.
Check out our frame-by-frame breakdown of the play in question below.