For those wondering what happened here: the winner managed to land a strong hit right between the ear of his opponent, which in turn sent impact waves through the internal ear. Therein, in addition to the sense of hearing, a liquid-bearing organ creates the sense of balance; perturbed by the impact, it was neutralized for a while, resulting in the opponent losing most of his equilibrium and being doomed to fall over.
This kind of move is illustrated for example in the manga Hagure Idol Jigokuhen, which I am not legally allowed to put a link to, mostly for smut reasons.

TFW you learn complex biology and martial arts lessons from a ecchi/hentai manga.