Ralph Gracie -- 5th degree Brazilian Jiu-Jitsu black belt and ex-MMA fighter -- has been charged with felony assault ... after allegedly knocking a Jiu-Jitsu champion out cold with an elbow, and then kicking him in the face.
The alleged incident went down December 15, 2018 on the sidelines of the International Brazilian Jiu-Jitsu Federation World Championships in Anaheim, CA.
Officials say Gracie -- whose grandfather Carlos Gracie developed Gracie Jiu-Jitsu -- attacked 5-time world champ Flavio Almeida ... elbowing him in the face, knocking him unconscious before kicking him in the face at least once.