S1 E2 | Georges St-Pierre vs. Matt Serra

While Canadian superstar Georges St-Pierre looked unstoppable atop the Ultimate Fighting Championship in 2007, the odds were stacked against Matt Serra, who was widely seen as a fighter on the decline; but when a bold reality competition show matched the underdog against the dominant champion, it produced one of the greatest upsets in UFC history - sparking a rivalry no one saw coming; Mario Lopez helps break down this feud with CM Punk, Michael Bisping, Miesha Tate and Stephen Thompson.