9. Conor McGregor v Jose Aldo – UFC 194 – 12/12/2015
In December 2015, Irish superstar Conor McGregor faced Featherweight champion Jose Aldo, then widely regarded as the greatest featherweight in history with a formidable 25-1 record.
McGregor’s pre-fight antics seemed to rile the Brazilian and the pair immediately engaged in the centre of the Octagon. Within seconds, McGregor countered Aldo with a left-hook, leaving him unconscious. McGregor landed two hammer fists as Aldo fell to the ground and the referee stopped the contest with just 13 seconds gone.