Simon ousts former champ del Potro

Though the U.S. Open adventure is only halfway completed, former champion Juan Martin del Potro was saying goodbye Sunday. The tournament's 2009 winner lost his third-round match to Frenchman Gilles Simon, 4-6, 7-6 (5), 6-2, 7-6 (3).

Given that del Potro still is working his way back from a surgically repaired wrist, which prevented him from defending his title last year and delayed his training regimen this season, the result could not be considered an upset. Simon, currently ranked six spots above del Potro at No. 12, tirelessly covered the court in the day's high humidity, wearing down del Potro in the 3-hour, 57-minute match.

"Anyways, I'm glad to be here, play this tournament," said del Potro, the 22-year-old Argentine and one of the Open's big crowd favorites. "I have what I feel a little sad now, because I lose. But I think my comeback is in good shape. I'm trying to improve my game."

Mostly, the day went according to form. Defending champion Rafael Nadal, troubled for only a short time by del Potro's fellow Argentine, veteran David Nalbandian, needed the minimum three sets to advance, 7-6 (5), 6-1, 7-5.

"I didn't have unforced errors," Nadal said. "I played well, just tried to wait for my moment. I'm happy about almost everything today. I think my movements worked pretty well, and the forehand worked really well, and the backhand, too."

No. 4 seed Andy Murray won his match's first 14 points in a row and cruised against 25th seed Feliciano Lopez of Spain, 6-1, 6-4, 6-2, setting up a Murray-Donald Young match.

John Isner, he of the extended set, needed a long tiebreaker in the first but then rolled to a 7-6 (9), 6-4, 6-4 victory over fellow American Alex Bogomolov Jr.

Next up for Isner, in the fourth round, will be Simon, and Nadal will be matched against 68th-ranked Gilles Muller of Luxembourg, a straight-sets winner over Igor Kunitsyn of Russia. No. 5 David Ferrer of Spain knocked out Germany's Florian Mayer in three sets and will play Andy Roddick.