Question: Who was an American boxer who was dubbed the "Uncrowned Champion of the Lightweights" who was never given the chance to fight for a large, extravagantly designed belt used primarily in combat sports such as boxing, mixed martial arts, and professional wrestling to signify the champions of the promotion or company ?
Sentence (from "List of current mixed martial arts champions"): At such times an interim champion may be crowned, or the belt may be awarded to the winner of a fight between top contenders.
Relevant evidence: No