Pound for pound one of the strongest fighters ever to step into the Octagon, wrestling ace Sean Sherk has some unfinished business with two of the top welterweights in the world – Matt Hughes and Georges St Pierre, the only fighters to ever pin a loss on the over 30-fight veteran from Minnesota. Winner of 12 of his last 13 bouts, ‘The Muscle Shark’ is aiming to make 13 unlucky for Diaz.