(BEIJING, August 14) -- Wednesday, August 13, saw the quarterfinal line-up determined in the Men's and Women's Singles and Men's Doubles at the Olympic Green Tennis Center. In the Women's Doubles, six of the last eight spots were decided. The United States is the only NOC still represented in all four Tennis events, while Austria and Serbia are still in both Singles events. Men's Singles, Third Round The world's top three players stayed on course for Olympic glory with comfortable victories. World No. 1 Roger Federer of Switzerland overcame stubborn resistance from Tomas Berdych of the Czech Republic 6-3, 7-6 (4). Rafael Nadal of Spain and Novak Djokovic of Serbia ended Russian hopes in this event. Nadal comfortably defeated Igor Andreev of Russia 6-4, 6-2. Djokovic became the first Serb to reach an Olympic quarterfinal with a 7-6 (3), 6-3 victory over Mikhail Youzhny of Russia. Fernando Gonzalez of Chile, Singles Bronze medallist in Athens, kept Chilean hopes alive with a crushing 6-0, 6-3 win over Olivier Rochus of Belgium, and now faces Paul-Henri Mathieu of France, who eliminated Germany's Nicolas Kiefer 6-3, 7-5. Women's Singles, Third Round No.4 seed Serena Williams of the United States was given a thorough workout by 18-year-old Alize Cornet of France, winning 3-6, 6-3, 6-4. In contrast, Serena's sister Venus Williams overcame a slow start before breezing past Victoria Azarenka of Belarus 6-3, 6-2 to reach the quarterfinals. New World No. 1 Jelena Jankovic of Serbia was tested by No.16 seed Dominika Cibulkova of Slovakia but came through 7-5, 6-1. All three Russian women in action on Day 4 went through to the quarterfinals. Elena Dementieva of Russia won over Caroline Wozniacki of Denmark 7-6 (3), 6-2, and Dinara Safina of Russia disappointed home fans by eliminating Zheng Jie of China 6-4, 6-3. Li Na kept Chinese hopes alive with a battling 4-6, 6-2, 6-0 victory over Kaia Kanepi of Estonia to reach the quarterfinals. Men's Doubles Second Round Top seeds Bob Bryan and Mike Bryan of the United States defeated Julian Knowle and Jurgen Melzer of Austria 7-6 (2), 6-4 to advance to a quarterfinal meeting with Chris Guccione and Lleyton Hewitt of Australia, who beat Rafael Nadal and Tommy Robredo of Spain 6-2, 7-6 (5). 2007 Wimbledon champions Arnaud Clement and Michael Llodra of France are also through to the quarterfinals after they crushed Andy Murray and Jamie Murray of Great Britain 6-1, 6-3. Federer is the only man remaining in both Singles and Doubles after he and Stanislas Wawrinka of Switzerland advanced to meet Mahesh Bhupathi and Leander Paes of India. Women's Doubles Second Round Australian Open champions Alona Bondarenko and Kateryna Bondarenko of Ukraine, seeded No. 6, were the first pair through to the quarterfinals with a 6-1, 6-3 victory over Olga Govortsova and Darya Kustova of Belarus. Lindsay Davenport and Liezel Huber of the United States, who have six Grand Slam Doubles titles between them, reached the last eight as did 2006 Australian Open and Wimbledon champions Yan Zi and Zheng Jie of China. The Men's and Women's quarterfinals in Tennis will be held at the Olympic Green Tennis Center on Thursday, August 14.