Roddick keeps moving on at US Open

NEW YORK — Andy Roddick's retirement party rocks on.

The 2003 U.S. Open champion, who last week announced he would retire after he was done at Flushing Meadows, advanced to the fourth round Sunday with a 7-5, 7-6 (1), 4-6, 6-4 victory over Fabio Fognini of Italy.

Roddick is in the round of 16 for the first time at a Grand Slam this season. But the upcoming test will be tougher. His next opponent is No. 7 seed and 2009 champion Juan Martin del Potro.

Against Fognini, Roddick put on an entertaining show, pumping his fist after a number of points and one time running over to the sideline and wagging his index finger at the crowd after a volley winner that gave him a 6-1 lead in the second-set tiebreaker.