Stanislas Wawrinka upset No. 3 David Ferrer 6-7 (3), 6-4, 6-1 Friday at the ATP World Tour Finals, maintaining the chance to reach the semifinals. He'll need top-ranked Rafael Nadal to beat Tomas Berdych in the evening match to advance to the final four. ''For sure, I'm going to be a big fan of Rafa,'' said No. 8 Wawrinka, who is enjoying a breakthrough season after years in the shadow of Swiss star Roger Federer. Defending champion Novak Djokovic has won Group B. The winner of Saturday's match between Juan Martin del Potro and Federer will join him in the semifinals. More...