AMMAN, JORDAN - SEPTEMBER 8 : Conor Mcgregor (Right) defeats Aron Jahnsen (Left) by Knockout at 3:29 of Round 1, Cage Warriors Fight Night 2, Fight Card on September 8, 2011 in Amman, Jordan

Modified Rules Boxing-UFC

Modified Rules Boxing-Ultimate Fighting

The first Modified Rules Boxing-Ultimate Fighting fight took place between Floyd Mayweather Jr and Conor McGregor, with two events – one Boxing and one Ultimate Fighting taking place in the fight, held on different nights. It follows the Irish tradition of Compromise Rules between Gaelic Athletic Association sports and other sports such as Australian Football, Shinty, Pelota, Baseball & Softball, Lacrosse and Golf.