Defending champion Novak Djokovic and 2003 titlist Andy Roddick were among the third-round winners Sunday at the U.S. Open.

The second-seeded former world No. 1 Djokovic drubbed No. 31 Julien Benneteau of France 6-3, 6-2, 6-2 in 97 minutes at Arthur Ashe Stadium. The Serbian has reached the round of 16 here for the sixth straight year.

Next up for the 25-year-old Djokovic will be Switzerland's Stanislas Wawrinka, the No. 18 seed. Wawrinka, a 2010 U.S. Open quarterfinalist, advanced Sunday with a 6-4, 6-4, 6-2 win over 14th-seeded Ukrainian Alexandr Dolgopolov.

Roddick, meanwhile, beat Italian Fabio Fognini 7-5, 7-6 (7-1), 4-6, 6-4 to extend his career at least one more match.

The 20th-seeded American, who announced he would retire after the year's final major, raced out to a 5-2 lead before Fognini captured the next three games to even the first set.

After fighting off a break point with an ace, Roddick held serve to go up 6-5 and then took the first set when Fognini sent a backhand volley into the net.

The duo exchanged breaks to begin the second set before holding serve the rest of the way, resulting in a tiebreak dominated by Roddick. The third set remained on serve until Fognini earned a break in the decisive 10th game, forcing a fourth set.

Fognini faced two break points in the seventh game. He save one but lost the other when he fired a ball into the net, giving Roddick a 4-3 lead. Roddick consolidated the break with a hold at 15 and finished off the three-hour match in his next service game. An ace gave him triple match point and he held off retirement with another unreturnable serve.

Roddick will face 2009 U.S. Open champion Juan Martin del Potro in the fourth round.

"He's a tough matchup for anybody because he hits such a big ball," Roddick said about del Potro. "I'm going to have to serve well, kind of try to rush him a little bit. When he gets into a groove and has time, he'll put a hurt on the ball."

The seventh-seeded Argentine defeated countryman Leonardo Mayer 6-3, 7-5, 7-6 (11-9).

Fourth-seeded Spaniard David Ferrer advanced to the round of 16 for the 10th consecutive Grand Slam with a 7-6 (11-9), 4-6, 6-3, 6-0 triumph over 2001 U.S. Open champion Lleyton Hewitt.

Ferrer's fourth-round opponent will be Richard Gasquet after the 13th-seeded Frenchman handled American Steve Johnson 7-6 (7-4), 6-2, 6-3.

Janko Tipsarevic also secured a spot in the fourth round. The eighth-seeded Serbian beat Slovenia's Grega Zemlja 6-4, 6-3, 7-5. He will face the 19th seed, Philipp Kohlschreiber, who outlasted No. 9 seed John Isner 6-4, 3-6, 4-6, 6-3, 6-4.