In doing a little fact-checking, I can in fact verify this is from an ad.
It should be noted, however, that A) Bruce Lee would be more than capable of replicating the effect in real life, if he happened to still be alive, and B) the credibility of the site kinda tanks for me when they can't differentiate between Karate and Kung Fu and they mispell "nunchaku" repeatedly.
In short, the guy was awesome, and even if it's not really him, who cares, it's pretty well-done.