No, not one who knew only Wing chun. They would get raped on the ground.
Yeah. You think so?? I think a wing chun practitioner who trains in defence against a bjj or any jiu-jitsu guy would kill him in a matter of seconds!! You are going on the premise that a wing chun guy would give him a chance to grab a hold of him and take him down. BIG MISTAKE,BUDDY!! A real wing chun master would not make that mistake (and neither would I, and I am not a master!!). You have to remember that a fight starts standing up, and that is where the wing chun master would have a MAJOR ADVANTAGE!! Usually Jiu-jitsu guys don't train in boxing, and MMA guys train in boxing,karate,kick-boxing and Jiu-Jitsu. Wing chun has the edge on ALL of these because of the basic nature of the style. It is a very efficient, very quick, and contrary to your belief and the belief of others, very powerful in a short distance (usually a matter of inches). Bruce Lee was a perfect example of that and he didn't even really follow the wing chun teachings(although he was taught the MODIFIED STYLE, with no footwork or entry techniques). He took his wc training and used the underlying principles and carried it over to JKD. All a wing chun master would have to do is enter, trap the hand and pound the shit out of the helpless sap and it would be over.