UFC champ Michael Bisping is being sued for allegedly choking a man at a 24 Fitness gym in Anaheim back in July ... TMZ Sports has learned.
According to the suit, Bisping went crazy on Antonio Georgakopoulos for "taking his weights" without asking during a workout.
Antonio claims Bisping called him all sorts of names including a "little punk" and an "idiot" -- and then dropped the "you don't know who I am?" line.
After the verbal tirade, Antonio claims Bisping grabbed him by the throat and began to squeeze -- cutting off oxygen.