Grand champion Hakuho suffered a big upset at the hands of rank-and-filer Hokutofuji on Sunday, the first day of the Autumn Grand Sumo Tournament.

Starting his first tournament as a Japanese citizen, Hakuho was immediately put on the back foot by top-ranked maegashira Hokutofuji, who has now beaten the record-holding champion twice in seven bouts.

Hokutofuji locked under Hakuho's left arm and drove the Mongolian off the raised ring with lethal timing, staying low to deny his opponent a belt hold.

"I charged in and was able to keep the pressure on going forward," Hokutofuji said. "I was up against a yokozuna so I had to make sure that I was able to get through and get in low. This time I felt I should go in lower than usual."

Hokutofuji, who faces yokozuna Kakuryu on Day 2, earned his sixth kimboshi prize for defeating a grand champion.

In the final bout of the day at Tokyo's Ryogoku Kokugikan, Kakuryu -- looking for a second straight top-division title -- took down komusubi Endo. Kakuryu held his ground against a solid initial charge and slapped Endo down to claim a textbook win.

(Hokutofuji defeats Hakuho.)

Among the ozeki in competition, Goeido easily pushed out No. 1 Aoiyama, while Tochinoshin was quickly felled by No. 2 Ichinojo.

Georgian-born Tochinoshin was unable to budge the 224-kilogram Mongolian and was thrown to the clay after slipping on his heavily taped left leg.

After each withdrawing without a winning record in Nagoya, Goeido and Tochinoshin are both fighting as demotion-threatened "kadoban" ozeki, needing at least eight wins to keep their rank.

Fellow ozeki Takayasu has pulled out of the entire 15-day meet with a left elbow injury.

Takakeisho, who is back in action after suffering a right knee injury in his ozeki debut in May, earned a hard-fought victory over No. 3 Daieisho. The sekiwake is seeking promotion straight back to sumo's second-highest rank with 10 or more wins in the tournament.

He fended off Daieisho's relentless pursuit, with each wrestler landing massive shoves and knocking each other around the ring. Adeptly keeping his balance, Takakeisho finally turned the tables by thrusting Daieisho down as he ran out of gas.

(Takakeisho (L) and Daieisho)

The other sekiwake, Mitakeumi, took a loss after being quickly driven out by No. 2 Asanoyama. Mitakeumi went for a slap-down, but Asanoyama secured a belt-hold on the initial charge and used it to drive Mitakeumi over the straw.

Komusubi Abi lost in his first top-division meeting with Tomokaze. Abi launched a flurry of shoves and slaps to push Tomokaze back, but the No. 3 maegashira remained poised and slapped Abi down.

In the lower ranks, Nagoya's juryo division champion and makuuchi newcomer No. 14 Tsurugisho beat No. 14 Toyonoshima to win in his top-tier debut.

No. 15 Azumaryu, who is making his first makuuchi appearance in 30 tournaments, also picked up an opening-day win against fellow top-division returnee, No. 15 Ishiura. No. 16 Yutakayama also marked his return with a win.