Terunofuji outmuscled Takayasu to extend the perfect start to his ozeki debut at the Nagoya Grand Sumo Tournament on Wednesday.
Terunofuji, looking to build on a stunning championship victory at the summer meet in May, had to grapple for control early on but never looked ruffled at Aichi Prefectural Gymnasium.
Meanwhile, Mongolian yokozuna Hakuho and Kakuryu also stayed perfect at 4-0.
The 23-year-old Terunofuji finally wore second-ranked Takayasu (1-3) down and bumped him over the ridge for a fourth win.
Terunofuji is aiming to become the ninth ozeki to win a championship in his debut.
Kakuryu was all business in forcing out top-ranked maegashira Tochinoshin (1-3) with little fuss.
Hakuho, chasing a 35th Emperor's Cup, also put on a controlling display, getting both arms around Sadanoumi (1-3) and shunting him out of the ring in the day's last bout.
In other action in the upper ranks, relegation-threatened ozeki Kotoshogiku's tournament hit a fresh nadir as he got shoved down to his third defeat by unbeaten sekiwake Tochiozan.
Kotoshogiku needs to win at least eight bouts here to preserve his rank for the next tournament.
In stark contrast, Goeido (2-2) never gave Ikioi a hope and bulldozed the winless No. 3 maegashira out for a quick-fire win.
Goeido pulled out of the Summer Basho with two days left owing to a fractured left shoulder and admitted in the lead up to Nagoya that he was struggling to get match fit.
Kisenosato improved to 3-1 with a routine force-out win over komusubi Takarafuji (1-3).
Mongolian sekiwake behemoth Ichinojo dropped to his third defeat after he was bellied over the ridge by komusubi Myogiryu (2-2).
