Djokovic and Sharapova advance at U.S. Open

  • Defending champion Novak Djokovic of Serbia cruised into the quarter finals of the U.S. Open on Wednesday after his fourth-round opponent Stanislas Wawrinka of Switzerland quit in the third set.

    Djokovic led 6-4 6-1 3-1 after an hour and a half on the Louis Armstrong Stadium court, when Wawrinka failed to continue playing after receiving medical help at the change of ends.

    Djokovic, who won the U.S. Open for the first time last year, will take on Juan Martin del Potro in Thursday's quarter-finals after the Argentine defeated retiring American Andy Roddick 6-7 7-6 6-2 6-4.

    Meanwhile, Maria Sharapova beat Marion Bartoli of France 3-6 6-3 6-4 to reach the semi-finals for the first time in six years.

    The Russian clawed her way back after losing the rain-interrupted first set and opening service game in the second set. She won in a two and half hour match that started on Tuesday afternoon and took 24 hours to complete.