With his third career title, the sekiwake will be considered for promotion to ozeki.
The Dewanoumi stable wrestler has a one-win lead over Terunofuji at the midway point.
The No. 3 maegashira knocks the lone grand champion out of the lead with a huge upset.
The Mongolian grappler is eager to prove he is a dominant force to be reckoned with as a lone yokozuna.
The 29-year-old Mongolian was ensured of his fifth title when Myogiryu lost an earlier bout.
Terunofuji loses for the first time in his debut at the sport’s highest rank.