Former champion Svetlana Kuznetsova ended the run of Hungarian teenager Agnes Szavay beating the 18-year-old 6-1, 6-4 to reach the US Open semifinals on Wednesday.

The Russian was too consistent for the world number 31, easing to victory in 67 minutes to set up a clash with her compatriot, sixth seed Anna Chakvetadze.

Szavay had taken the first set off Kuznetsova in the final of the WTA event in New Haven just before the US Open only to retire with a back injury, but she looked nervous early on in her first Grand Slam quarterfinal.

In another quarterfinal, Russian Anna Chakvetadze breezed past Shahar Peer of Israel 6-4, 6-1 to enter semis.

Nadal ousted

Meanwhile Second seed Rafael Nadal wilted under the strain of a fearless forehand by David Ferrer and top seed Justine Henin maintained her recent grand slam mastery over Serena Williams in a wild Tuesday at the US Open.

Ferrer blasted 48 winners to shock his Spanish compatriot 6-7, 6-4, 7-6, 6-2 in a three-hour, 28-minute fourth-round match on Arthur Ashe Stadium that ended at 1:50 a.m. on Wednesday.

Henin, who knocked out Serena at both Wimbledon and the French Open, outslugged her opponent 7-6, 6-1 to reach to the semifinals against either Venus Williams or Jelena Jank-ovic.

The 25-year-old Ferrer, who had lost his last four matches against Nadal, clinched victory when the world number two hit a backhand lob beyond the baseline.

Nadal, a three-times French Open winner, who has been hampered by a left knee injury, had no answer for the heavy forehand from Ferrer.

Elsewhere on the men's side, third seed Novak Djokovic advanced to the Open quarters for the first time with a 7-5, 7-6, 6-7, 6-1 triumph over Argentine Juan Monaco. Other fourth-round winners included former world number one Carlos Moya of Spain and Argentine Juan Ignacio Chela, who will face Ferrer in the quarterfinals.

Great atmosphere

World number one Henin survived a set point at 5-6 before storming through the tiebreaker 7-3. Williams never recovered, falling behind 3-0 in the second set.

"I was a bit concerned during the first set because I wasn't aggressive eno-ugh," Henin said. "Then from the tiebreak until the end, I played unbelievable tennis.

 Henin's win was her first over Williams on a hard court and levelled her career record against the double US Open champion at 6-6.

Djokovic, 20, needed just under four hours to subdue Monaco, a 23-year-old who had never won a match at Flushing Meadows before this year.

RESULTS

US Open results (prefix denotes seeding):
Men’s singles, fourth round: 15-David Ferrer (Spa) bt 2-Rafael Nadal (Spa) 6-7(3-7), 6-4, 7-6 (7-4), 6-2; 3-Novak Djokovic (Ser) bt 23-Juan Monaco (Arg) 7-5, 7-6 (7-2), 6-7 (6-8), 6-1; 17-Carlos Moya (Spa) bt Ernests Gulbis (Lat) 7-5, 6-2, 6-7 (5-7), 6-4; 20-Juan Ignacio Chela (Arg) bt Stanislas Wawrinka (Sui) 4-6, 6-2, 7-6 (8-6), 1-6, 6-4. 
Women's singles (quarterfinals): 1-Justine Henin (Bel) bt 8-Serena Williams (US) 7-6 (7-3), 6-1; 4-Svetlana Kuznetsova (Rus) bt Agnes Szavay (Hun) 6-1, 6-4;  6-Anna Chakvetadze (Rus) bt 18-Shahar Peer (Isr) 6-4, 6-1.
Mixed doubles (semifinals): Meghann Shaughnessy (US)/ Leander Paes (Ind) bt Liezel Huber (RSA)/ Jamie Murray (Bri) 6-7 (4-7), 7-6 (7-5), 10-5; Victoria Azarenka/ Max Mirnyi (Ber) bt 3-Yan Zi (Chi)/ Mark Knowles (Bah) 7-6 (7-5), 6-4.