Video has emerged of a sickening brawl outside an Adelaide nightclub which left one man unconscious and patrons ducking for cover.

Exclusive video shows terrified diners scramble to get out of the way as the brawl erupted outside of Sugar nightclub on Rundle street just after 10pm on Friday night.

View photos Photo:7News More

View photos Photo:7News More

A man can be seen violently smashing a chair to the ground multiple times as he yelled an expletive-laden tirade.

Other alleged culprits can be seen throwing chairs and glasses at their victims in the relentless attack as cafe owners feared their customers could be next.

View photos Photo:7News More

View photos Photo:7News More

Story continues