hitting sombody hard enough on the nose can blind him from pain for a couple of minutes .
other trick is to use only 1 or 2 fingers and push them very quick in the side of the neck and push trough to the spine.
there are a lot of nerves in the back there .
but you canonly use 2 fingers max since the you need to put max force on a small very small part of the body.
doing this right will make the guy just go flat for a couple of minutes.
(not unconsious, or not from pain ,but he will go trough his knees.