A brawl outside an upscale South Philly strip club left one man unconscious as the attacker left the scene in a cab. 

Video released by police shows a group of men leaving Club Risque on the 1700 block of S. Columbus Boulevard in late June. 

Some sort of argument erupts.  One member of the group -- wearing khaki pants, no less -- starts throwing punches. In the video, the fight starts at about 1-minute mark.

A beefy brawler sends one victim to the ground. The video doesn't show it, but police say that when a second man jumped in, he was knocked unconscious.

The suspect is described as a white male in his mid- to late- 20's standing 6-feet tall, muscular build. 

Police are asking anyone with information to call. 

Watch the video below.