Mike Heffner, who represented the winning bidder, told The (Louisville) Courier-Journal, the new owner had "strong ties to Pittsburgh" and paid $632,500 for the jersey.
Mazeroski won the 1960 series for the Pirates with his legendary homer in the bottom of the ninth inning of Game 7 against the New York Yankees. Now 77, the Hall of Famer was in the audience at the annual Louisville Slugger Museum and Factory Live Auction.
Heffner held off three other proxy bidders and was declared the winner after offering $550,000. A 15 percent buyer's premium was tacked on to raise the final tab to $632,500.
But Heffner told The Courier-Journal his client was pleased. "It's the foundation of Pittsburgh baseball history," he said.