Argentina's Juan Martin Del Potro advanced to the US Open quarter-finals by sending American Andy Roddick into retirement with a 6-7 (7/1), 7-6 (7/4), 6-2, 6-4 victory on Wednesday at Arthur Ashe Stadium.
Roddick, whose only Grand Slam title came at the 2003 US Open, said last week he would retire after the tournament and the end came against the 2009 champion.
The seventh-seeded South American booked a Thursday quarter-final date with defending champion Novak Djokovic, the Serbian second seed who advanced 6-4, 6-1, 3-1 when Swiss 18th seed Stanislas Wawrinka retired.