McIlroy threw the ball into the stands off the 18th green at Hoylake and it was caught by Englishman Lee Horner. Horner consigned the ball to golf auctioneer Green Jacket Auctions, with the ball selling in the early morning hours on Sunday.
The auction company's co-founder, Ryan Carey, said that the price paid for the ball is the second-highest ever paid for a golf ball, narrowly missing what a collector paid in April 2011 for a vintage Bobby Jones autographed ball ($55,865).
"There was a lot of interest in this ball," Carey said. "We had 22 different bidders from countries across the world, including Ireland, Australia and countries in Asia."
Carey said the buyer wanted to stay anonymous, but did disclose that it was won by an American.
The ball, which has the word "RORS" printed on it, was confirmed to be McIlroy's ball by his sponsor Nike.
Carey said not many tournament-winning balls have come to the collector's marketplace because they are either kept by the golfer or even lost in a bag after a round. He said he hopes that the money generated from the McIlroy ball will encourage golfers to save their balls and for some to eventually be made available to the public.
As for McIlroy, it seems like he's content with rewarding fans after his wins. After winning the Bridgestone Invitational earlier this month, McIlroy once again threw his ball into the crowd.
Said Carey: "Maybe this is Rory's thing. If he wins the PGA on Sunday, some lucky fan might have another $50,000 ball."