Movies were false. They fought until one forced the other to surrender, and the fight itself was enough for the peasants. Usually it was them who decided whether or not he lived, and generally they let him live. IF they hated him, then it went up to the emperor or whoever else decided it, whether he died. Just because you didn't die doesn't mean you can't lose. If I throw the guy to the ground and point a sword at his neck and he can't fight back, I've won.