The fight marked Ali’s return to competitive boxing after he was stripped of his boxing license and World Boxing Association title for refusing to be drafted into the US military to fight in Vietnam seven years earlier.
The belt first became public in 1988, when the contents of Ali’s late boxing trainer Drew “Bundini” Brown’s storage lockers were sold at auction.
This is one of only two known WBC belts held by Ali after the fight; the other remains in a private collection.
And this is the highest price for a sports collectible sold at Heritage auctions.
“After hours of watching two bidders go back and forth on this belt, this proved to be a fight worthy of the Rumble itself,” Chris Ivey, director of sports auctions at Heritage, said in a press release.
“We are thrilled that this extraordinary piece of boxing history – the history of sport, the history of culture – has found such an exceptional guardian to share it with the rest of the world.”
Irsay already owns several other items from Ali’s career, including a 1965 gown that first went by the name Muhammad Ali and his shoes from the 1975 Trilla in Manila fight against Joe Frazier.
The Colts owner has spent millions building his collection, which features memorabilia from the worlds of sports, music, literature and politics.
He presents this collection, along with a new addition, to the public on August 2 in Chicago and September 9 in Indianapolis.
