Bruce Lee's celebrity often meant he was challenged by a number of stunt men and martial arts extras that were looking to make a name for themselves. Lee would normally diffuse the challenges without combat, but was forced to answer a few that were particularly persistent.
Bob Wall, a USPK karate champion and co-star of Enter the Dragon (note: hes the guy who gets his ass kicked in the youtube vid i posted), recalled a particularly serious encounter that materialized after a Martial Arts extra repeatedly taunted Lee. The extra yelled that Lee was "a movie star, not a martial artist", that he "wasn't much of a fighter" and said it was "easy to see his martial art wasn't any good." Lee answered his taunts by asking him to jump down from the wall he was sitting. Wall described Lee's opponent as "a gang-banger type of guy from Hong Kong!," a "damned good martial artist," and observed that "He was fast, he was bigger than Bruce, and he was strong!" [17]
Wall would recall the confrontation in detail:
"This kid was good. He was no punk. He was strong and fast, and he was really trying to punch Bruce's brains in. But Bruce just methodically took him apart."[18]
"I mean Bruce kept moving so well, this kid couldn't touch him...Then all of a sudden, Bruce got him and rammed his ass into the wall and swept him, knee dropped him[dropped one of his knees into his opponent's chest], arm locked him[locked his arm out straight], and nailed him in the face repeatedly."[19]
After his victory, Lee gave his opponent lessons on how to improve his martial art. His impressed opponent would later say to Lee, "You really are a master of the martial arts."[18]