Djokovic into US Open last-eight

NEW YORK (AFP) –

Defending champion Novak Djokovic, pictured in action on September 4, reached the US Open quarter-finals on Wednesday when Swiss 18th seed Stanislas Wawrinka retired from their fourth-round match.

Defending champion Novak Djokovic reached the US Open quarter-finals on Wednesday when Swiss 18th seed Stanislas Wawrinka retired from their fourth-round match.

Djokovic was 6-4, 6-1, 3-1 ahead when Wawrinka called it quits and he will next face either 2009 champion Juan Martin Del Potro, the Argentine seventh seed, or 2003 winner Andy Roddick for a place in the semi-finals.