Hakuho had to dodge a bullet but toppled newly promoted komusubi Kakuryu to stay perfect with a 5-0 record at the Summer Grand Sumo Tournament on Thursday.
Asashoryu, meanwhile, remained hot in pursuit by picking up his fourth win with a demolition of Tamanoshima in the penultimate bout as he aims for his career 24th title and first in two meets.
Hakuho, who won the spring title in March with an undefeated record, made the critical mistake of allowing his fellow Mongolian a belt grip, and the komusubi wasted little time trying to muscle the yokozuna over the edge at Ryogoku Kokugikan.