Grand champion Asashoryu overpowered Bulgarian Kotooshu on Saturday to remain in the lead at the New Year Grand Sumo Tournament.
Mongolian Asashoryu forced the No. 4 maegashira back after the faceoff and used a right arm throw to send Kotooshu toppling off the raised ring at Tokyo's Ryogoku Kokugikan Arena.
Asashoryu, who won five of six tournaments last year, improved to 7-0 while Kotooshu dropped to 3-4.
But it may have been a costly win for the Mongolian yokozuna, who left the ring favoring his right shoulder and wincing in pain.
In other major bouts, Mongolian Kyokutenho remained one win off the pace at 6-1 when he hauled down Russian Roho in an earlier bout. Roho, a fifth-ranked maegashira, dropped to 4-3.
Kyokutenho is tied for second place along with sekiwake Tochiazuma.
Ozeki Kaio's nightmare tourney continued when he was overwhelmed at the faceoff by komusubi Kotomitsuki.
Kaio, who came into the 15-day meet looking for promotion to the sport's highest rank, dropped to an unimpressive 3-4 and has no chance to move up the ranks.
Kotomitsuki, who got both arms around Kaio at the faceoff and muscled his opponent out over the straw ridge, picked up his third win against four losses.
Chiyotaikai (4-3), who needs a winning record here to maintain his ozeki status, was handed his second straight loss in a bout against top maegashira Iwakiyama (5-2).