George Foreman's 1968 Olympic Gold Medal Hits Auction Block

Before George Foreman knocked out Joe Frazier to become the heavyweight champion or fought Muhammad Ali in one of the most memorable fights ever ... Big George won Olympic gold in 1968 -- and now the medal's on the block!!

Foreman, who was just 19, was dominant in Mexico City, steamrolling his opps on the way to winning the '68 Summer Games.

George's toughest challenge came in his first fight against Poland's Lucjan Trela -- in the round of 16 -- a bout he won 4-1.

From there, it was easy work for Foreman. He badly hurt Ion Alexe from Romania in the quarterfinals, forcing the referee to stop the contest in the third.

In the semifinals, Big George put Italy's Giorgio Bambini on his ass three times, winning by second-round knockout.

It was much of the same in the finals ... Foreman thoroughly destroyed Jonas Cepulis of the Soviet Union, winning by referee stoppage in the second round, securing the gold!

The medal from the October 26, 1968, bout is on the block at Lelands Auction, where it has already been bid on multiple times, despite not closing until next Saturday.

As for how Lelands got the historic piece, it's an interesting story.

Foreman was apparently neighbors with the consignor's mother back in Houston in the 1970s, when George asked if he could store boxes in her garage, according to Lelands. She obliged.

Years later, when the neighbor's daughter went through some of her mom's things, she came across a bunch of G.F.'s stuff, including trophies, a driver's license, and the gold medal!

Now the late-great Foreman's medal can be yours.