Japanese wrestler Kaori Icho has suffered defeat for the first time in 189 matches - a run spanning 13 years.
The 31-year-old - Olympic champion at 63kg in 2004, 2008 and 2012 - lost to Mongolian student Orkhon Purevdorj, 21.
The loss, in the final of the 58kg category at the Golden Grand Prix event in the Siberian city of Krasnoyarsk, gives rivals for the 2016 Games hope.
"There's enough time to put things right," said Japan national team director Kazuhito Sakae.
"I'm relieved it wasn't the Olympics. I believe she can win her fourth-straight Olympic title," added Sakae.
Icho did forfeit a match in 2007, but last lost a contest on the mat in 2003.
Facebook did not exist and Twitter was three years away from arriving online when the 10-time world champion last walked away from a bout as a loser.
After the 10-0 technical fall loss to Purevdorj she said she had not been allowed to wrestle her way and wanted to use the defeat as a chance "to grow".