It's obvious that rugby is a physical game, and that there can be many fights.
It seems though, that English lock Dave Attwood took things a little further during the first half of England's victory over Wales with a fight against an invisible force. Attwood gets up from a ruck, takes two swings when there is no one around him, and then gets laid out by the invisible punch.
It just gets funnier and funnier when you watch it.
(Click on the image if it doesn't play)