A Sean Taylor autographed football card -- the only certified signed card ever released -- just fetched a whopping $13,000 at auction ... TMZ Sports has learned.
Here's the deal ... the card was released as part of Panini's 2017 Flawless collection ... but the actual autograph was signed on a 2004 Topps rookie card.
We'll explain ...
A rep for Panini tells us Panini obtained the 2004 card (which was signed AFTER it was released through Topps) and independently authenticated the autograph. Then, Panini cut the card down to fit in the Flawless card frame. It was then inserted into a random card pack and pulled by a lucky collector.
Once pulled, the card made its way to eBay where the starting bid was $900. It received 51 total bids and finally sold for $13,000! The identity of the buyer has not yet been revealed.
Of course, Taylor passed away in 2007 -- but had never signed a card that was officially distributed through a major trading card company.
Obviously, he's still extremely popular with football fans and collectors.
By the way ... if you're wondering what happened to the top half of the original 2004 Topps card -- we're told it hit the cutting room floor.