Nikita Tszyu defeats Diaz by knockout in the sixth round in a fight that draws controversy, according to multiple Australian outlets. All three reports agree on the outcome and timing of the stoppage, stating that Tszyu knocks out Diaz in the sixth round. The coverage also highlights that the result is accompanied by controversy, though none of the provided excerpts specify the nature of the dispute (such as officiating, scoring, or conduct during the bout). Beyond the shared description of the finish, the sources presented here do not include further details about the fight’s key moments, judges, or the specific points of contention. Overall, the reporting converges on the same core facts: Tszyu wins by sixth-round knockout, and the fight is surrounded by controversy.