Attention, tennis fanatics -- the racket Novak Djokovic used in his 2012 Australian Open final against Rafael Nadal is up for auction ... and if ya got a spare six figures lying around, you can get in on this rare item!!

TMZ Sports has learned the racket is on the auction block with SCP Auctions ... and it's the same equipment he used on January 29, 2012, when he faced Rafa in Melbourne, Australia.

Not only was this match between two of the best players, but it lasted almost six hours -- the longest Grand Slam Final to date.

Novak famously celebrated the historic win by ripping his shirt off after he dropped his racket -- and now the very same piece is up for grabs at a hefty price.

We're told the HEAD Speed racket -- which features an 18x20 string pattern and a 27-inch frame, complete with a Novak label -- is expected to fetch more than $200K, and bidders only have a few days to make an offer.

"SCP Auctions is honored to offer the racquet Novak used in this epic final that many consider the greatest match in tennis history," the company said.

The auction company said the anonymous consignor sat right behind Novak's player bench during the match ... and was given the racket as a "token of gratitude."

Now, it's a gift that keeps on giving -- happy bidding!!