Frank Shamrock (born Frank Alisio Juarez, III; December 8, 1972) is a former American mixed martial artist. Shamrock was the first to hold the UFC Middleweight Championship (later renamed the UFC Light Heavyweight Championship) and retired a four-time defending undefeated champion. Shamrock was the No. 1 ranked pound for pound UFC fighter in the world during his reign as the UFC Middleweight Champion.[2] Shamrock has won numerous titles in other martial arts organizations, including the interim King of Pancrase title, the WEC Light Heavyweight Championship and the Strikeforce Middleweight Championship and remains the only athlete in history to hold titles in every major sports league.