In the day's final bout at Ryogoku Kokugikan, komusubi Ama used an arm throw to send compatriot Hakuho sprawling to the dirt surface.

"I just went on the attack from the beginning," Ama said. "I was able to knock him off balance and it's good to start with a win."

With Mongolian grand champion Asashoryu sitting out the 15-day tournament, Hakuho enters as the clear favorite, but he didn't get the start he wanted against the plucky komusubi wrestler.

Hakuho is gaining a reputation for losing on the opening day of tournaments and will need to be sharper if he wants to lift the Emperor's Cup at the completion of the Autumn tourney.

Asashoryu is serving a two-tournament suspension for playing in a charity soccer match earlier this summer after bowing out of an exhibition tournament. He claimed he was injured.

In other major bouts, Kotomitsuki, who was making his debut at sumo's second highest rank of ozeki, got off to a winning start when he got a grip of Tochinonada's belt and threw the No. 2 maegashira off the raised ring.

Top maegashira Homasho upset ozeki Kaio, forcing the veteran grappler to the edge and shoving him out for an opening-day win.

Ozeki Kotooshu of Bulgaria engaged Tokitenku in a slap-fest at the center of the ring and eventually prevailed when he used an arm throw to send the top maegashira toppling off the raised ring.

Ozeki Chiyotaikai overpowered komusubi Kisenosato to post an easy win.