Greg the Barber -- the guy who famously knocked out Suge Knight -- was choked out in a violent nightclub altercation ... when a bouncer ran up from behind him and put him in a sleeper hold.
** Warning: This footage contains explicit language and violence **
The footage -- first posted on Friday by HoodNews.org -- shows Greg conducting an interview for some sort of Internet show in front of Wonderland in Hollywood ... when a bouncer knocks into him from behind.
Clearly upset, Greg aggressively confronts the bouncer -- when ANOTHER bouncer rushes in from behind and puts a death grip around Greg's neck ... until he passes out.
When Greg wakes up, he tries to find the man who attacked him ... even throwing punches at one point.