Anderson Silva -- The Rock Would Kick My Ass!!

Anderson Silva knows his limits in the ring ... and those limits are about 6'5, 260 lbs ... telling TMZ Sports that Dwyane "The Rock" Johnson would beat the crap out of the UFC legend if they fought.

Silva was out in L.A. when we asked the man who Dana White called "the greatest mixed martial artist of all time" if his octagon expertise would be enough to take down the freak of nature that is The Rock.

Watch the video -- Anderson wants no part of Mr. Johnson, not hesitating in the least when we drop the question on him.

FYI -- Anderson also (kinda) picks a winner between Mayweather and Pacquiao (like it's ever gonna happen) and tells us who's hotter out of Beyonce and Rihanna.