Sekiwake Kotoshogiku handed Mongolian yokozuna Hakuho a stunning second consecutive defeat to blow the title race wide open and keep alive his hopes of promotion to ozeki at the Autumn Grand Sumo Tournament on Friday.
A win for Hakuho, who saw his unbeaten record ended by nemesis Kisenosato on Thursday, would have put him on the brink of a 20th Emperor's Cup.
But Kotoshogiku had other ideas and came out with all guns blazing in the day's finale, steaming into the yokozuna and bumping him back over the straw ridge to set up an intriguing climax at the 15-day Tokyo meet.
Kotoshogiku moved into a tie for the lead with Hakuho at 11-2, while sekiwake Kisenosato, Georgian grappler Gagamaru and 11th-ranked Kitataiki remained in contention at 10-3.
Kotoshogiku is hoping to fill the void left by Kaio, who was the last remaining Japanese ozeki before he hung up his mawashi at the Nagoya Basho in July.
Having scored bonus points with an upset win against Hakuho, a 12th victory on Saturday against Harumafuji will likely be enough to secure promotion for the Kyushu meet in November.
Kisenosato prevailed with a forceout win over and 11th-ranked Gagamaru, while Baruto (9-4) won an all-ozeki battle, flexing his muscles to force out Nagoya champion Harumafuji (8-5), who came into the tournament gunning for promotion to yokozuna only to blow his chance with four losses in the first week of the tourney.
In other bouts, Kitataiki was beaten by ozeki slayer Homasho, who scored with an "oshitaoshi" frontal push down technique to secure a majority of wins.