Flushing Meadows, NY (My Sportsbook) - Fourth seed Novak Djokovic, No. 5 seeded American Andy Roddick and eighth seed Nikolay Davydenko reached the third round at the U.S. Open, the final Grand Slam event of the year.

The Serbian Djokovic, the 2007 runner-up, topped Australian Carsten Ball, 6-3, 6-4, 6-4.

Roddick beat Frenchman Marc Gicquel, 6-1, 6-4, 6-4 in the final match of the night. That sets up a third-round encounter with 6-foot-9 American John Isner, who beat Turkey's Marsel Ilhan, 6-3, 6-4, 7-6 (7-1). The Roddick-Isner matchup figures to be one that will have plenty of aces as two of the hardest servers battle each other for the third time in their careers with Roddick leading, 2-0.

"John's been playing a lot better," said Roddick. "It's going to be a completely different matchup. I'm not going to be able to break as much as I have these first couple matches. It's going to come down to a couple of points here or there."

Roddick, who lost to Federer at the epic Wimbledon final this year and won the U.S. Open in 2003 before finishing as the runner-up in 2006

The Russian Davydenko dismissed Czech Jan Hernych, 6-4, 6-1, 6-2 on the grounds at the Billie Jean King USTA National Tennis Center.

Also, 21st-seeded American James Blake saved three set points in the third and picked up a victory over Olivier Rochus of Belgium, 6-4, 3-6, 7-6 (8-6), 6-3.

Tenth-seeded Spaniard Fernando Verdasco eased his way into the round of 32 with a 6-3, 6-0, 6-3 spanking of helpless Frenchman Florent Serra. The lefthanded Verdasco is fresh off his hardcourt title in New Haven last week.

Verdasco will battle former world No. 2 Tommy Haas in the round of 32.

A 20th-seeded Haas moved on with a 6-4, 6-4, 7-6 (7-3) victory over American Robert Kendrick, while surging American Sam Querrey, seeded 22nd here, edged out countryman Kevin Kim 7-5, 6-7 (6-8), 6-4, 6-4 on Day 4. Querrey headed to New York as the points winner in the US Open Series and was last week's New Haven runner-up to Verdasco.

American qualifier Jesse Witten reached the third round by overcoming Argentine Maximo Gonzalez 6-7 (3-7), 6-4, 7-5, 6-2. The 276th-ranked Witten had not won an ATP match prior to this week. His next opponent will be Djokovic.

Sweden's Robin Soderling, Spaniard Tommy Robredo and Czech Radek Stepanek, seeds, 12, 14 and 15, respectively, all advanced to round three. Soderling won the first two games of his match when Spain's Marcel Granollers retired due to a back injury. Robredo downed fellow countryman Guillermo Garcia-Lopez, 6-2, 4-6, 6-2, 6-4, while Stepanek ousted Argentine Leonardo Mayer, 7-6 (7-5), 6-3, 6-4. Soderling next plays Querrey, while Robredo battles Blake.

Philipp Kohlschreiber. the 23rd seed from Germany, defeated Somdev Devvarman of India, 6-3, 6-4, 0-6, 6-2. Switzerland's Marco Chiudinelli got past Russian Mikhail Youzhny, 2-6, 7-6 (7-4), 6-4, 6-3.

The second round is scheduled to conclude here on Friday, with matches coming for second-seeded Andy Murray, third-seeded Rafael Nadal, sixth-seeded Juan Martin del Potro and seventh-seeded Frenchman Jo-Wilfried Tsonga.

Murray, last year's U.S. Open runner-up to Roger Federer, will meet Chilean Paul Capdeville, while the former top-ranked Nadal, who lost to Murray in last year's semifinals in Flushing, will battle tough German Nicolas Kiefer. Nadal is a six-time major champion, including this year's Aussie Open crown.

The 2009 U.S. Open champ will collect at least $1.6 million.