Wimbledon • No. 1-seeded Novak Djokovic, top, and No. 2 Andy Murray have yet to lose a set at Wimbledon and, the way things have been going at the All England Club this fortnight, that's quite an accomplishment. Twelve-time Grand Slam champion Rafael Nadal was beaten in the first round. Roger Federer, owner of a record 17 major titles, went out in the second, as did four-time major champ Maria Sharapova. "Everyone was a bit on edge, a little bit uptight," reigning U.S. Open champion Murray said. > D3