The boxing legend is pissed off at White -- claiming Dana blocked UFC legend Georges St-Pierre from participating in a boxing match with Oscar.
St-Pierre seemingly confirmed the move in a recent interview with CinemaBlend -- saying, "I understand that Dana didn't want me to fight."
He added, "However, it would have been fun. Because my career as a professional fighter, to become the best in the world in mixed martial arts, is done. "
"However, to rather fight a boxing match under the rules that Triller put on against the legendary Oscar De La Hoya? For me, it would have been a dream come true, because he is my second favorite boxer of all time, behind 'Sugar' Ray Leonard."
Dana hasn't publicly commented on the matter -- but Oscar is fuming ... and Friday, he called out the UFC honcho on Twitter.