Komusubi Kaio saddled yokozuna Takanohana with his first loss of the Summer Grand Sumo Tournament on Friday, leaving nine wrestlers tied for the lead at 5-1 six days into 15-day tournament.
Kaio, who earlier upset two ozeki and ozeki hopeful Miyabiyama, shoved Takanohana into the ringside seats at Tokyo's Ryogoku Kokugikan for a share of the lead with his fifth win against a lone loss to yokozuna Akebono.
Takanohana appeared to have the upper hand as he marched Kaio toward the edge of the ring with neither wrestler able to secure control of the other's sash.
Kaio responded by turning away from his opponent and forcing Takanohana off balance with pressure on the back of the grand champion's left arm.
When the Yokozuna attempted to recover his balance, Kaio finished him off with a shove from the side that sent him topping off the raised ring.
In other key bouts, Akebono rammed out No. 4 maegashira Tamakasuga (3-3) for a fifth win and ozeki Takanonami (5-1) backed out Kyokushuzan (1-5) after nearly getting thrown down by the tricky fourth-ranked maegashira from Mongolia.
Sekiwake Miyabiyama (5-1), meanwhile, weathered a barrage of slaps and thrusts from Takatoriki (2-4) and shoved the elusive komusubi over the edge to remain on track for ozeki consideration.
Ozeki Dejima (4-2) buried his shoulder deep into the chest of top maegashira Tochinonada (2-4) at the face-off and bulldozed him out of the ring for his third win in a row.
Sekiwake Tochiazuma was on the receiving end of a storm of thrusts and slaps from Chiyotaikai (4-2) until he was able to catch the ozeki's left arm in mid-thrust and hurl him across the ring for a fourth win.
Mongolian No. 6 maegashira Kyokutenho ended a three-day losing streak by muscling out Kinkaiyama (2-4) to even his record at 3-3.
