LONDON — Neither No. 1-seeded Novak Djokovic nor No. 2-seeded Andy Murray has lost a set heading into the Wimbledon quarterfinals.

The way things have been this fortnight, that's actually quite an accomplishment.

Rafael Nadal, a 12-time Grand Slam champion, was beaten in the first round. Roger Federer, owner of a record 17 major titles, went out in the second round, as did four-time major champ Maria Sharapova. Five-time Wimbledon winner Serena Williams' 34-match winning streak ended in the fourth round.

And on and on it's gone, with no top-20 player other than Murray left on his side of the draw, and a record-equaling number of withdrawals or mid-match retirements because of health problems.

Djokovic faces No. 7 Tomas Berdych on Wednesday. Murray plays 54th-ranked Fernando Verdasco.