Instructor Joshua Wang was just finishing a class, when he gave a crook free lesson.
Wang tells a local television station in Pittsburgh that a man walked into his school carrying a gun.
Wang grabbed the man's head and twisted it.
A student tried to take away the weapon.
But Wang says the robber was "very strong" and managed to get free, then run.
Wang notes he's from China and says he has never seen anything like it.
