Stanford 24-23 USC, 2007
We could go even further back in history to when Jim Harbaugh recruited Pete Carroll's son for the University of San Diego back in 2006 - but really that is just part and parcel of football.
The first time the two coaches faced up against each other on the field came when Jim Harbaugh took his Stanford side to overwhelming favourites USC in a NCAA match up.
Pete Carroll was in charge of the Trojans and had overseen a dominant program, coaching his team to two of the previous three BCS title games.
Stanford therefore, came into the game with many predicting a rout for USC.
But Jim Harbaugh navigated his team to an historic 24-23 win over Carroll - scoring 17 points in the final quarter to comeback from a nine point deficit.
USC dropped from #1 in the coaches poll in the aftermath and Harbaugh gained plaudits for the upset.
Carroll still went on to lift the Rose Bowl that year but Harbaugh made an impression with this win there is no doubt.