After a quick TKO victory over decorated judoka Yoon Dong-Sik in the opening round, Sakuraba suffered a particularly devastating yet controversial loss against Ricardo Arona in the quarterfinal of the tournament in June 2005. Although Sakuraba put Arona on his back and seemed to put to work his signature jumping stomps, the heavier and stronger Arona soon overpowered him, landing a series of brutal knees to the head, as well as hard soccer kicks to the face. The Brazilian's toenail accidentally slashed open the skin over Sakuraba's left eye, which Ricardo then capitalized on by squeezing the cut and digging his finger into it in order to force the doctor stoppage. The Japanese tried to keep on, but Arona hit another flurry of knees to the head, and ended the fight landing soccer kick after soccer kick, rendering Kazushi's face severely swollen and bloody. Arona won by unanimous decision.