Depends on what the combatants are fighting for. It's like the rabbit and the fox. The fox usually loses the chase because he's only running for his supper while the rabbit is running for his life. The guy who WANTS to win will win. The only REALLY dangerous weapons are man and the mind.
Forget the 10 minute fights you see in the movies. Someone well-trained in martial arts can disable an opponent in 2-3 blows. Disarm, certainly - and even kill.