Tiger Woods' backup putter from his sensational 2002 season has sold for US$393,300, Golden Age Golf Auctions said on Sunday.
The price paid for the Scotty Cameron putter has reportedly made it the most expensive golf club ever sold.
The putter was personally produced by Cameron for Woods and comes with a letter of authenticity.
Woods won five tournaments, including the Masters and the U.S. Open, in 2002.
Fifteen-times major champion Woods practiced and experimented with the putter but did not use it in competition, the auction house said.
"There are only a handful of pieces of sports memorabilia that we can be relatively certain will be collected for centuries - Babe Ruth's (baseball) bat; Muhammad Ali's (boxing) gloves; Michael Jordan's (basketball) shoes," the auction house said in a statement.
"When it comes to golf, there's one such item that we would add to the list above all others - Tiger Woods' red dot Scotty Cameron putter."
The putter Woods has used for the majority of his 15 major victories is still in his possession and would fetch millions if it was to ever go on the block, the auction house said.
A differently designed backup putter used by Woods sold for US$155,000 more than a year ago.
Woods, 45, is still recovering from the multiple leg injuries he suffered in a car crash in February near Los Angeles.