The body knows what fighters don't: how to protect itself. A neck can only twist so far. Twist it just a hair more and the body says: "Hey, I'll take it from here because you obviously don't know what you're doing. Lie down now, rest, and we'll talk about this when you regain your senses". It's called the knockout mechanism.
Morgan Freeman - Eddie Scrap-Iron Dupris

“- Laura Charles: I thought that maybe it would be a great idea if I got myself a bodyguard. You know, like someone to guard my body? What girl could do worse that to have her own real life kung fu master?
- Leroy Green: I am no master.
- Laura Charles: You sure look like a master to me.”
Vanity - Laura Charles
Taimak - Leroy Green

“I've never prized safety, Erich, either for myself or my children. I prized courage.”

Frank Morgan - Professor Viktor Roth

“Every man I meet wants to protect me. I can't figure out what from.”
Mae West - Flower Belle Lee

“- Wayne Carter: I never argue - with a lady.
- Flower Belle Lee: Play it safe, huh?”
Dick Foran - Wayne Carter
Mae West - Flower Belle Lee