NEW YORK, Sept 3: Venus and Serena Williams served their way into the US Open quarter-finals with impressive straight-sets victories Sunday, setting up a possible clash between the American sisters in the final four.

Venus never lost her serve during a 6-4, 6-2 drubbing of Ana Ivanovic, while Serena stopped France’s Marion Bartoli 6-3, 6-4 by blasting 10 aces and landing 73 percent of her first serves.

A Venus-Serena match-up would be their fourth at Flushing Meadows and the first since meeting in the 2005 fourth round.

Standing in the way of Serena’s possible clash with Venus is top seed and world No 1 Justine Henin, who demolished 15th seed Dinara Safina 6-0, 6-2 in just 59 minutes.

On the men’s side, second seed Rafael Nadal said he continued to suffer from nagging injuries to both knees but his ailments hardly apparent during a 7-6, 6-2, 6-1 victory over Frenchman Jo-Wilfried Tsonga.

Nadal made only 14 unforced errors and never lost his serve against the 74th-ranked Tsonga.

In the fourth round, Nadal will face compatriot David Ferrer, who needed just under four hours to defeat Argentine David Nalbandian 6-3, 3-6, 4-6, 7-6, 7-5.

Third seeded Novak Djokovic of Serbia recovered from his four-hour, 44-minute victory over Radek Stepanek on Friday to ease past Argentine Juan Martin Del Potro 6-1, 6-3, 6-4.

Other third-round winners included Stanislas Wawrinka, Juan Ignacio Chela, Carlos Moya and Juan Monaco.

Eighth seed Tommy Robredo of Spain was eliminated, falling 6-1, 6-3, 6-2 to 88th-ranked, 19-year-old Ernests Gulbis of Latvia.

Venus Williams has not lost a set during her four matches and in the quarter-finals will face 2006 semi-finalist Jelena Jankovic, a 6-4, 4-6, 6-1 winner over 19th seed Sybille Bammer of Austria.

Third seed Jankovic was broken in the first game of the third set but swept the next six to set up a clash with Williams, who has lost her last three meetings with the Serb.

Ivanovic, the French Open finalist, was unable to keep up with the punishing serve or angled groundstrokes by Venus.

She said the 12th seeded American might be ready to claim her first Open crown since winning the second of two straight titles in 2001.

Sunday’s results (prefix number denotes seeding):

Men’s singles:

Third round: Ernests Gulbis (Latvia) beat 8-Tommy Robredo (Spain) 6-1, 6-3, 6-2; 3-Novak Djokovic (Serbia) beat Juan Martin Del Potro (Argentina) 6-1, 6-3, 6-4; 17-Carlos Moya (Spain) beat Philipp Kohlschreiber (Germany) 4-6, 7-5, 7-6 (7-5), 4-6, 6-4; Stanislas Wawrinka (Switzerland) beat Robby Ginepri (US) 5-7, 6-4, 4-6, 6-4, 6-3; 23-Juan Monaco (Argentina) beat Agustin Calleri (Argentina) 7-6 (7-5), 6-2, 6-4; 2-Rafael Nadal (Spain) beat Jo-Wilfried Tsonga (France) 7-6 (7-3), 6-2, 6-1; 15-David Ferrer (Spain) beat 24-David Nalbandian (Argentina) 6-3, 3-6, 4-6, 7-6 (7-5), 7-5; 20-Juan Ignacio Chela (Argentina) beat 12-Ivan Ljubicic (Croatia) 6-4, 6-7 (5-7), 2-6, 6-3, 6-3.

Women’s singles:

Fourth round: 3-Jelena Jankovic (Serbia) beat 19-Sybille Bammer (Austria) 6-4, 4-6, 6-1; 1-Justine Henin (Belgium) beat 15-Dinara Safina (Russia) 6-0, 6-2; 12-Venus Williams (US) beat 5-Ana Ivanovic (Serbia) 6-4, 6-2; 8-Serena Williams (US) beat 10-Marion Bartoli (France) 6-3, 6-4.—Reuters