Seabiscuit -- Legendary Saddle Auctioned Off ... Rakes In $104k!

The saddle that was strapped to Seabiscuit's back when the legendary horse won his very last race in 1940 has just sold at auction for more than $100,000 ... TMZ Sports has learned.

It's the saddle ridden by jockey Red Pollard at the 1940 Santa Anita Handicap -- one of the most dramatic races in Seabiscuit's career. After losing the race several times before, Seabiscuit dug deep and emerged victorious in what would be his very last race.

In fact, the race was featured in the 2003 Disney movie about the thoroughbred.

According to Lelands, the company behind the auction, the final sale price was $104,260.06.

So far, the identity of the buyer has not been released.