Shohei Ohtani 50/50 Ball Sells For $4.39 Million, Most Expensive Ball Ever

Shohei Ohtani's historic 50/50 ball has a new owner -- the highly coveted piece of baseball memorabilia just sold for a whopping $4.39 MILLION at auction ... making it the most valuable ball in sports history.

Bidding on the item -- which was cosigned with Goldin Auctions -- ended on Tuesday ... and the final number far surpassed the $3 million paid for Mark McGwire's 70th home run ball from 1998, the previous record holder for balls sold at auction.

The winning offer was $3.6 million ... but including the 22-percent buyer's premium, it reached a staggering $4,392,000 price tag.

The new owner's identity has not been revealed ... but we're gonna take a wild guess and say it's an extremely rich Ohtani or baseball fan.

Ken Goldin said the listing garnered bids from all over the globe ... which would make sense, as Ohtani's an international superstar.

Ohtani reached the major accomplishment against the Miami Marlins on Sept. 19 ... and despite an ongoing legal battle among spectators over the ownership of the ball, Goldin was able to reach an agreement with all parties involved to move forward with the auction.

The opening bid was $500K ... but Goldin told TMZ Sports he knew it would fetch much more -- and that it did!