UFC 137 features the return of top ranked welterweight Nick Diaz, as he faces former two-division UFC champion BJ Penn. Plus two heavyweight matchups are on tap, as Cheick Kongo meets Matt Mitrione, and Mirko Cro Cop takes on Roy Nelson.

Four of mixed martial arts' most revered superstars delivered two of the best fights of 2011 as headliners of UFC 139 in San Jose. In the main event, former Strikeforce and PRIDE two-division champion Dan Henderson returned to the UFC for a five-round epic against former UFC light heavyweight title holder Mauricio ''Shogun'' Rua. And in the co-main bout, it was bombs away for Sanshou master Cung Le and Brazil's ''Axe Murderer,'' Wanderlei Silva, in a brawl you have to see to believe. Plus, former world champs collide, as Urijah Faber meets Brian Bowles.