Roger Federer overcame an ailing back to beat James Blake in a one-set exhibition Tuesday. Federer rallied from 3-1 down to win 7-6, taking the tiebreaker 10-7. His victory came days after a sore back contributed his struggles at the Masters Cup, where he failed to reach the semifinals. John McEnroe and Bjorn Borg also played at the "Showdown of Champions," which included four one-set matches. More...