Yokozuna Asashoryu got down to business with a convincing win over komusubi Tosanoumi but ozeki Musoyama and Kaio fell victims to first-day losses at the Summer Grand Sumo Tournament on Sunday.

The 22-year-old Mongolian titan, who failed to claim the Emperor's Cup in his debut as grand champion in March, took complete control of his larger opponent in the day's final bout at Tokyo's Ryogoku Kokugikan.

Asashoryu, who largely disappointed with a 10-5 performance last time out, retreated slightly after the charge but quickly composed himself as he moved the komusubi firmly over the straw bales for a two-armed frontal force out and a first-day victory.