Anthony Bourdain wasn't just a legendary chef ... he was the most influential celebrity Brazilian Jiu-Jitsu practitioner -- who helped introduce the martial art to the masses -- so says the guy whose family founded BJJ.
TMZ Sports talked to Rener Gracie -- whose grandfather, Helio Gracie, created Gracie Jiu-Jitsu a.k.a. Brazilian Jiu-Jitsu -- about Bourdain's impact on his family's sport.
FYI -- Rener's coached Ronda Rousey and UFC star Brian Ortega ... and occasionally hit the mats with A.B. (check out their training sesh below from 2014).
Bourdain wasn't the only celeb to train ... Ashton Kutcher, Vince Vaughn, Ed O'Neill, Kelly Slater, Guy Ritchie, and Keanu Reeves practice BJJ -- but according to Gracie, Anthony was the most important.
"I think that Anthony Bourdain, A, because of his enthusiasm and his ease of communication, and B, because of his age, is responsible for more people doing Jiu-Jitsu and beginning Jiu-Jitsu, than probably any other celebrity ever who's not a professional fighter."
Rener goes on to say Bourdain's passing leaves a void that might never be filled.
"All of Jiu-Jitsu, and even MMA, lost an ambassador that we may never replace in terms of what he brought and how openly and passionately he spoke about the incredible lifestyle and sport we all love."