Spanish top seed Rafa Nadal overcame stubborn second-set resistance from compatriot Tommy Robredo to reach the Shanghai Masters quarterfinals 6-1, 6-4 Thursday. Second seed Novak Djokovic again looked impressive as he continued his imperious form in China with a 6-4, 6-2 thrashing of German qualifier Rainer Schuettler. As the debate about the draining effects of the long men's season continued with Stanislas Wawrinka and Gael Monfils becoming the sixth and seventh players to retire injured from the $3.24 million tournament. World No. 2 Nadal cantered through the first set but lost his serve at the start of the second. The 23-year-old Australian Open champion is nothing if not a fighter, however, and he battled back into the set in a marathon third game before breaking again for a 5-4 lead and serving out for victory. Djokovic, who will move up to No. 3 in the world next week, proved in winning the season-ending Masters Cup here last year that he has the legs to outlast his rivals. The Serbian won the China Open title last weekend and his victory over Schuettler, which set up a tie against Gilles Simon, was his ninth in a row on Chinese soil. Sixth seed Nikolay Davydenko defused Fernando Gonzalez's serve with his mobility along the baseline to grab a sixth win in six meetings against the Chilean 6-3, 7-5. Simon, seeded eighth, was the only one of three Frenchmen to get through the third round after he notched up a 6-3, 6-4 win over Czech Tomas Berdych. Robin Soderling upset error-prone French fifth seed Jo-Wilfried Tsonga 6-3, 6-3 in their encounter under the open roof of the Qizhong central arena. Soderling is among a handful of players still in with a chance of claiming one of three remaining spots up for grabs at the season-ending World Tour Finals in London next month. Swiss Wawrinka was losing 3-6, 7-6, 4-2 to Czech Radek Stepanek when abdominal pains caused him to withdraw, while French 11th seed Monfils was down 6-2, 3-0 to Ivan Ljubicic when he quit because of a back injury. Ljubicic faces Nadal next. Wozniacki in quarters In Osaka, top-seeded Caroline Wozniacki of Denmark overpowered Britain's Katie O'Brien 6-0, 6-1 Thursday to advance to the quarterfinals of the Japan Women's Open. Wozniacki converted six of nine break points in a match that lasted just 44 minutes at Utsubo Tennis Center. The US Open finalist will face Canada's Aleksandra Wozniak in the quarterfinals of the $220,000 tournament. Sixth-seeded Wozniak struggled past Taiwan's Chang Kai-chen 7-5, 7-6 (2). American veteran Jill Craybas recovered from a shaky start for a 2-6, 6-2, 6-0 win over France's Mathilde Johansson. Craybas will next face third-seeded Australian Samantha Stosur, who defeated Japan's Akiko Morigami 6-1, 6-2. Pennetta, Radwanska advance In Linz, top-seeded Flavia Pennetta retained her slim chance of reaching the WTA Championships by defeating Anna-Lena Groenefeld of Germany 6-3, 4-6, 6-2 to reach the Generali Ladies quarterfinals Thursday. The 11th-ranked Italian needs to win the tournament as well as next week's Kremlin Cup in Moscow to qualify for the elite season-ending event. She next plays unseeded Ioana Raluca Olaru of Romania, who rallied to defeat German qualifier Julia Goerges 3-6, 6-2, 7-5. Second-seeded Agnieszka Radwanska also advanced but younger sister Usrzula couldn't join her and set up a family clash. Agnieszka defeated Alize Cornet of France 6-4, 7-5 in the second round, while Urszula Radwanska lost to seventh-seeded Lucie Safarova of the Czech Republic 6-4, 6-4. Agnieszka will now face Safarova. Also moving on was No. 3 Yanina Wickmayer of Belgium, who rallied to beat Alexandra Dulgheru of Romania 2-6, 6-3, 6-1. Serena, Hewitt in Sydney World No. 1 Serena Williams, Frenchman Gael Monfils and four-time champion Lleyton Hewitt have been confirmed to play in the WTA/ATP Sydney International in January, organizers said Thursday. Serena will be joined in the women's draw by defending Sydney champion and world No. 5 Elena Dementieva of Russia and world No. 8 Victoria Azarenka of Belarus. Tournament officials have also secured French showman Gael Monfils and leading Australian player Lleyton Hewitt in the men's draw.
