After a decision loss to Ryuta Noji in March 1999, Pettas returned to K-1 to compete in the eight-man tournament at the K-1 World Grand Prix 2000 in Nagoya on July 30, 2000. He stopped fellow karateka Ricky Nickolson with a low kick in the quarter-finals before going on to face Jérôme Le Banner in the semis. The end of the fight was somewhat bizarre. Le Banner knocked Pettas down twice, forcing the referee to stop the match. Upon the second knockdown, Pettas returned to his feet sharply and prepared to punch Le Banner only to stop. Le Banner then replied by striking Pettas with a right hook, knocking him unconscious.
