"Cinderella Man" James Braddock's heavyweight title belt auctions later on Saturday.
Braddock became the unlikeliest of world heavyweight champions when he defeated Max Baer in New York's Madison Square Garden in 1935.
Braddock would only fight in two more bouts
It was a huge upset, which completed Braddock's journey from penniless club boxer to number one in the world.
Journalist Damon Runyon called him the Cinderella Man following the 15 round unanimous decision win.
Ring Magazine presented the 10/1 shot with the belt selling at SCP Auctions, which has received bids of $28,533 with less than 24 hours left.
"With direct Braddock family provenance, this exquisite, hand-woven belt remains exceptionally well-preserved in all-original condition after 81 years," explains the auctioneer.
"It is one of the earliest championship boxing belts ever offered at auction and certainly ranks as one of the most important pieces in the 125-year history of the sport."
A pair of 1953 Rocky Marciano bout-used and signed gloves is also up for grabs. Marciano wore them in his first heavyweight title defence, when knocking out "Jersey" Joe Walcott in the first round at the Chicago Stadium.
Bids stand at $14,615.
Leading pieces of boxing memorabilia historically attract large bids. The sector is dominated by Muhammad Ali. The gloves Ali wore when defending his heavyweight title in 1965 against Floyd Patterson sold for $1.1m in 2014, a boxing memorabilia record.
A baseball uniform Babe Ruth wore to promote the 1939 World's Fair in New York also features at SCP. Bids stand at $97,437.
The auction ends at 8pm EST.
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