COMPLEX SAYS: These two Cali natives were actually friends and training partners before their friendship turned into one of the most-heated rivalries in UFC history. The feud began when Dana White tried to schedule a bout between Ortiz, the UFC light heavyweight champion at the time, and Liddell, who was the number one contender. Ortiz kept saying a busy schedule was the reason a fight date could not be set. The bout eventually happened in 2004 at UFC 47 with Liddell winning by TKO. Two years later they had a rematch with Liddell winning by TKO again. We guess pain is love? Most recently the two have taken their squabbles viral.