Tour Manager Sues Katt Williams For Knocking Him Out

Katt Williams' tour manager says the the comedian delivered a knockout blow to his face ... and now he's suing for assault and battery.

Mark Williams claims Katt went off on him back in May, according to a new lawsuit filed in L.A.

Williams -- who doesn't mention any relation to Katt -- claims Katt hit him "with such force and power that he was rendered unconscious for a period of 90 seconds."

The lawsuit doesn't say where or why the alleged scrap went down, but it must have hurt like hell because Williams adds ... Katt was "wearing his diamond rings which served as a brass knuckles weapon."

Williams claims he suffered a concussion, loose tooth, and unspecified facial and head injuries.

Katt Williams is a bad mofo…..