Hakuho capitalized on a slip-up by co-leader and fellow Mongolian yokozuna Harumafuji on Friday to take sole possession of the lead with two days left at the Kyushu Grand Sumo Tournament.
Harumafuji saw his unbeaten record end when he was taken out by ozeki Kisenosato, and Hakuho took full advantage, barging out ozeki Kakuryu in the day's finale at Fukuoka Kokusai Center.
Hakuho, who is gunning for his 28th career title, leads with a 13-0 mark, one ahead of Harumafuji and two ahead of Kisenosato.
Kisenosato, who faces Hakuho on Saturday, kept his slim championship hopes alive when he shrugged off a slap to the face after the charge and got his left hand onto the back of Harumafuji's mawashi belt.
The ozeki lost his grip but gained enough momentum to force the yokozuna over the straw ridge.
Seeking a sixth Emperor's Cup, Harumafuji, who has suffered from inconsistent form since being promoted to yokozuna, meets Kakuryu on Saturday.
Hakuho, meanwhile, failed in his first attempt to throw down Kakuryu, but he kept a firm grip on his countryman's belt and worked him over the ridge.
Kakuryu is tied at 9-4 with Chiyotairyu, Ikioi and Bulgarian grappler Aoiyama.
In the lower ranks, Osunaarashi, sumo's first African-born wrestler, sent fellow rank-and-filer Takarafuji packing with a vicious thrust to the throat to close in on a winning record on his makuuchi debut. Both men have 7-6 marks.
