Question: What was the nickname of the reigning, retired heavyweight champion at the time of the Fitzsimmons vs. Sharkey Heavyweight Championship boxing match?
Sentence (from "UCW-Zero Heavyweight Championship"): On February 26, 2011, the UCW-Zero Heavyweight Championship was around the waist of Los Mochis Paco until it was stolen by Tyler Cintron after Junior X attacked Paco.
Relevant evidence: No