Kisenosato lost his cool but still emerged the winner in a heated bout against rival ozeki Kotoshogiku, retaining his share of the lead with rank-and-filer Tochiozan on the ninth day of the Summer Grand Sumo Tournament on Monday.

Yokozuna Hakuho lost to Toyonoshima in another shocker, falling to his fourth defeat, as his campaign for his 23rd career title continues to unravel in nightmarish fashion.

Kisenosato, who is trying to become the first Japanese wrestler in more than six years to claim an Emperor's Cup, improved to 8-1 going into the final six days, while four, including ozeki pair Kakuryu and Kotoshogiku, trail at 7-2.

In the day's penultimate bout at Ryogoku Kokugikan, Kisenosato made Kotoshogiku pay for his delaying tactics, the Naruto stable ozeki clearly angry for having to reset after a false start.

Kotoshogiku got his left hand inside for an upper grip but could not finish off as Kisenosato dragged him to the dirt with a shoulder swing, sending him a final glare for good measure.

Nothing went right for Hakuho in the day's finale as the yokozuna's ineffectual shoves were absorbed by Toyonoshima (5-4) before the sekiwake tossed him over the ridge with a neck throw, and a quick ringside conference confirmed the defeat.

Hakuho, the man who famously won 63 consecutive bouts two years ago, left the building — perhaps never to regain his once dominant form.

"I wanted to try to shake him up," said Toyonoshima, who had won only one of the pair's previous 20 meetings. "I tried to go at full throttle."

Mongolian ozeki debutant Kakuryu dropped to a second defeat against Aminishiki (5-4).