DALLAS, TX.- A heavyweight bout lasted well into Sunday morning. And when the final bell rang at Heritage Auctions, Indianapolis Colts owner and philanthropist Jim Irsay walked away with the championship belt — specifically, Muhammad Ali's World Boxing Council (WBC) heavyweight championship belt earned in his victory over George Foreman in 1974's legendary Rumble in the Jungle in Zaire.

The WBC belt realized $6,180,000, the highest price for a sports collectible sold at Heritage Auctions. It was offered alongside other historic Ali items in Heritage's July 21-23 Summer Sports Catalog Auction.

"After several hours of watching two bidders go back and forth over this belt, this proved to be a battle worthy of the Rumble itself," says Chris Ivy, Heritage's Director of Sports Auctions. "We're just thrilled this extraordinary piece of boxing history — of sports history, of cultural history — found such an exceptional caretaker who will now share it with the rest of the world."

Indeed, as Irsay tweeted Sunday morning, he will add the belt to his celebrated collection of historical and pop-culture artifacts currently touring the country. The belt will be displayed on August 2 at Chicago's Navy Pier and on Sept. 9 in Indianapolis. "Proud to be the steward!" Irsay tweeted.

Two Muhammad Ali World Boxing Council belts are known to exist, each presented retroactively to Ali in 1976 for his 1974 victory over Foreman. One of those belts remains in a private collection. The title belt sold Sunday, like so many of the most extraordinary Ali artifacts circulating the hobby today, was first acquired in 1988 when the contents of Ali's late boxing coach Drew "Bundini" Brown's storage lockers were sold at auction.

Heritage's catalog called this belt "arguably the most important boxing award ever made available at public auction," with good reason. Ali was drafted to fight in Vietnam but refused induction into the U.S. Armed Forces, insisting his religion forbade him from serving. Said Ali in April 1967, "I will not go 10,000 miles to help kill innocent people." The cost to Ali was enormous: He was stripped of his boxing license — and his World Boxing Association title.

The comeback fight with Foreman, which took place in Kinshasa, Zaire, on Oct. 30, 1974, was "arguably the greatest sporting event of the 20th century," Grantland once noted. As documented in the Academy Award-winning 1996 film When We Were Kings, the event was a spectacle that began with a three-day music festival in September and concluded with Ali's eighth-round knockout of the man who entered the ring the overwhelming favorite.

The belt joins other Ali artifacts in Irsay's collection, including his 1965 walkout robe that first bore his new name, his shoes from the 1975 Thrilla in Manila vs. Joe Frazier and his fight-worn gloves from a 1966 title defense in Germany.