The funnyman, who occasionally hits the road for big-venue comedy shows, tested out new material on 40 lucky comedy fans at Meltdown Comics on Sunset Boulevard.
Reports suggest Williams, who was recently named Stand-Up Icon at the Comedy Awards in New York, performed a fast-paced, high-energy routine for almost 45 minutes.
One eyewitness tells WENN, ""He didn't seem to be there with anyone or to see anyone. It appeared he simply wanted to try out new stuff on a small audience. He was fantastic. The comedy was very current and topical.""