"What's your deal?" - 2009
The moment in which sporting competitiveness turned to disdain (for a moment at least).
Again this incident took place in college football surroundings as Stanford returned to the Colliseum for the first time since 2007 and again came away with a W.
But this time the game was far less close, Harbaugh's team posting 55 points against the Trojans who only managed 21 in response.
While a humiliating defeat would be painful enough for a coach like Pete Carroll to swallow, it was one specific play which Carroll - and many others - took objection to.
Stanford were up 48-21 with six minutes to play - victory was assured.
But instead of sending in the kicker for the conversion, Jim Harbaugh called for his team to go for the two-point conversion instead.
The play failed but it did not go down well with Carroll and the Trojans.
As the game ended and the two coaches came together in midfield, Carroll's first words to Harbaugh?
These three words have come to symbolise the rivalry between them.