Golfer: Arnold Palmer
Event: 1966 U.S. Open
Even one of the game's greats had moments of epic failure. Heading into the back nine of the 1966 U.S. Open Championship, Palmer had a cushy seven stroke lead over Billy Casper. At that point, Casper was just trying to hold off Jack Nicklaus for second place. In a bold, but careless move, Palmer decided to go for Ben Hogan's open scoring record of 276, leading to a series of overly-ambitious shots.
By the 15th hole, Palmer's lead shrank to -3 after Casper nailed a 20-foot putt for birdie. After that, the meltdown was full-on, as he bogeyed the next two holes to insure a playoff, which he lost the following day. Palmer never won another major after that nightmarish weekend in June of '66.