Question: What is the name of the American mixed martial artist competing in the UFC, born in 1984, and winning the Middleweight Championship against Chris Weidman?
Sentence (from "Luke Rockhold"): A two-time world champion, Rockhold also won the Strikeforce Middleweight Championship by defeating Ronaldo Souza on September 10, 2011 via unanimous decision.
Relevant evidence: No