Federer, Nadal in round three

Roger Federer, Andy Murray, Rafael Nadal and Novak Djokovic all advanced to round three, but Roddick's US Open preparations suffered a blow with his 7-6, 7-6 defeat to fellow American Sam Querrey.

The world number five was not the only big-name disappointment, though, with seventh-seeded Frenchman Jo-Wilfried Tsonga despatched 7-6, 6-2 by Australian qualifier Chris Guccione.

Roddick, beaten by Federer in the Wimbledon final last month, blew set points in the first-set tiebreak and then led by an early break in the second set but could not press home the advantage.

The world number 26 Querrey will face Australia's Lleyton Hewitt, a 6-3, 6-3 winner over Benjamin Becker, in the next round.

Swiss world number one Federer won 6-3, 7-5 against Jose Acasuso.
Federer will play Spaniard David Ferrer for a place in the quarter-finals.  Murray beat Spaniard Nicolas Almagro 7-6, 6-2, saving a set point at 6-5 down before easing through the second set to secure a meeting with Czech Radek Stepanek, a 4-6, 6-3, 6-1 winner over Russian Marat Safin. Nadal edged out Italian Andreas Seppi 7-6, 7-6.

Fourth seed Novak Djokovic scaraped past Ivan Ljubicic 7-6, 6-4, despite 15 aces from the Croatian to secure a meeting with Jeremy Chardy of France. Paul-Henri Mathieu set up a meeting with Nadal by beating Ivo Karlovic of Croatia 7-6, 6-4.

Bhupathi-Knowles win

Mahesh Bhupathi and Mark Knowles moved into the doubles quarterfinals, edging past Feliciano Lopez and Fernando Verdasco in a tough three setter 5-7, 6-4, 12-10 in one hour and 29 minutes on Wednesday.

Leander Paes and Lukas Dlouy are slated to meet the Spanish duo of David Ferrer and Tommy Robredo in their second-round encounter.