Impressive Upside-Down Kick KO

This kick is so impressive and difficult-looking that I kind of doubt that it's practiced. It seems like one of those moves that just seemed like a good idea in the moment, like, "Hey, why don't I do a front flip whilst swinging my legs really fast and see what that does?" What it does, it turns out, is knock an opponent the hell out. This could have ended up on the blooper reel if it missed, but it hit and looks very cool as a result.