Ricardo Arona (; born 17 July 1978) is a Brazilian former professional mixed martial artist, submission grappler and 4th degree Brazilian jiu-jitsu (BJJ) black belt practitioner. A two-time World IBJJF Jiu-Jitsu champion in the lower belts, Arona is a World black belt medallist and a triple-crown winner of the ADCC Submission Fighting World Championship (winning his weight class, the absolute division, and the superfight). A professional MMA fighter from 2000 until 2009, Arona competed in PRIDE Fighting Championships, RINGS and was a member of Brazilian Top Team. He is the former RINGS Middleweight Champion, as well as the 2001 RINGS Middleweight Championship Tournament Winner, and 2005 PRIDE Middleweight Grand Prix Runner-Up. Arona has notable wins in both MMA and submission grappling competition over Tito Ortiz, Jeff Monson, Renato Sobral, Vitor Belfort, Mark Kerr, Kazushi Sakuraba, Wanderlei Silva, Dan Henderson, Alistair Overeem, Murilo Rua, Jeremy Horn, Guy Mezger, and Dean Lister. His four ADCC titles and his clean record of 13–0 after not losing a single point in a match, earned Arona in 2021 a place in the inaugural class of the ADCC Hall of Fame, Background Arona was born on 17 July 1978 in Niteroi, Brazil. He trained in judo and karate before transitioning into Brazilian jiu-jitsu (BJJ) after seeing a vale tudo fight at the age of 13. Arona came to Carlson Gracie at the age of 18 when he was a purple belt and would go on to win numerous titles in BJJ and submission wrestling. Arona is the only ADCC competitor to go undefeated without losing a single point in any match. Mixed martial arts career Fighting Network RINGS Soon after ADCC, Arona joined Fighting Network RINGS, a Japanese mixed martial arts promotion. His debut match would against aging sambo champion Andrei Kopylov, who Arona defeated by unanimous decision after controlling him positionally for most of the match. He then beat Jeremy Horn by split decision, and went to participate in the King of Kings tournament, but was eliminated at the first round by Fedor Emelianenko in Arona's first loss. Although the Brazilian controlled Emelianenko with takedowns and superior ground game, as RINGS's ruleset gave more scoring to aggression than positional control, Fedor was awarded the decision for attempting more submissions during the match. Arona's next opponent was professional wrestler Hiromitsu Kanehara. Ricardo overwhelmed him with punches and takedowns, while Kanehara repeatedly reversed to top position and