When a fight lasts a long time, often a very long time, things can get a bit...different. Elaborate sword duels can turn into bar brawls. A gunfight becomes a fistfight. Improvised Weapons start appearing. Things get brutal, or just plain silly, or just plain wrong.
A common comedy variation is for a brawl between two grown men to devolve into a childish slap fight.
Kind of the opposite of the [...] [tvtropes.org]