TOKYO - Sumo's greatest-ever champion Hakuho has decided to retire over persistent knee trouble, Japanese media reported Monday, leaving a gaping hole at the top of the ancient sport.
The Mongolian-born 36-year-old has won a record 45 tournaments -- 13 more than anyone else in history -- but has been sidelined by injury for most of the year.
He made his only appearance of 2021 at July's Nagoya Grand Sumo Tournament, going unbeaten to win the title after missing all or part of the previous six competitions.
He and 17 other wrestlers from his stable were forced to miss the next tournament, which ended Sunday, after a coronavirus outbreak.
Local media said that Hakuho has decided to retire because of a right knee injury, bringing the curtain down on his illustrious career after 1,187 wins.
The Japan Sumo Association said it had no comment.
Born Munkhbat Davaajargal and the son of an Olympic silver-medal freestyle wrestler, Hakuho came to Japan at age 15 to enter the sumo world.
He debuted in 2001 and won his first top-division title in May 2006, before reaching the sport's highest rank of yokozuna at age 22 in July 2007.
His battles with fellow Mongolian yokozuna Asashoryu -- the pantomime villain to Hakuho's popular good guy -- helped breathe new life into the ancient sport, with attendances booming.
Asashoryu retired in 2010 but Hakuho went from strength to strength, overtaking the legendary Taiho's record of 33 tournament wins in January 2015.
Hakuho outlasted fellow yokozuna Harumafuji, Kakuryu and Kisenosato, but his impending retirement will leave only one wrestler -- Terunofuji -- at sumo's highest rank.
Hakuho acquired Japanese citizenship in September 2019, giving him the right to run his own sumo stable after retirement.
He leaves the sport as sumo's longest-serving yokozuna, having fought his 1,000th bout at the rank in July 2020.