Nadal struggles against Kiefer

Rafael Nadal is through to the third round of the US Open despite his beaten opponent claiming the Spaniard is below his best.

Rafael Nadal of Spain pumps his fist against during the game against Nicolas Kiefer of Germany at the US Open tennis tournament in New York on September. 4, 2009.

Rafael Nadal is through to the third round of the US Open despite a performance that had his beaten opponent claiming the Spaniard is below his best. The six-time Grand Slam event winner was happy to face a challenge in the second round before ousting Germany's Nicolas Kiefer 6-0, 3-6, 6-3, 6-4. Nadal's win meant this is the first Grand Slam tournament in the 41-year Open era with the top 16 men into the third round. In that third round, Nadal will meet compatriot Nicolas Almagro.

Perhaps rusty after a long layoff, perhaps still dealing with pain even if he says he is all right, the No. 3-seeded Nadal struggled at times on Friday. "Was a very good practice for me, no?" Nadal said, calling the match "a very good test". Things did not come easily for Nadal, who is trying to complete a career Grand Slam by winning the US Open for the first time. "He was getting a little bit tired. I could see it, I could feel it. He didn't move so good," Kiefer said. "But at the end of the day, it doesn't count if you play good or bad. A win is a win, a loss is a loss."

Meanwhile Serena Williams has withstood a strong test from Maria Jose Martinez Sanchez of Spain 6-3, 7-5 to advance to the fourth round. It was an awkward match in Arthur Ashe Stadium for defending champion Williams, full of counterpunches from the game's biggest power hitter. "I heard a guy in the crowd saying, `Stop hitting lobs', so I didn't hit any more lobs after that," Williams said.

"My lob was not working today." Receiving at 5-all in the first set, Williams chipped back serves, made a few passing shots and found herself at deuce for the eighth time in a game that lasted 12 minutes. Martinez Sanchez finally wore out, double-faulting twice in a row to give up the break and, essentially, the match.

Men Second Round Andy Murray (2), Britain, def. Paul Capdeville, Chile, 6-2, 3-6, 6-0, 6-2. Rafael Nadal (3), Spain, def. Nicolas Kiefer, Germany, 6-0, 3-6, 6-3, 6-4. Juan Martin del Potro (6), Argentina, def. Jurgen Melzer, Austria, 7-6 (6), 6-3, 6-3. Jo-Wilfried Tsonga (7), France, def. Jarkko Nieminen, Finland, 7-5, 6-3, 6-4. Gilles Simon (9), France, def. Thomaz Bellucci, Brazil, 6-3, 6-2, 6-4. Fernando Gonzalez (11), Chile, def. Josselin Ouanna, France, 6-4, 6-7 (5), 6-3, 6-4. Gael Monfils (13), France, def. Andreas Beck, Germany, 6-3, 7-5, 6-3. Marin Cilic (16), Croatia, def. Jesse Levine, United States, 4-6, 2-6, 6-0, 6-3, 6-0. Tomas Berdych (17), Czech Republic, def. Horacio Zeballos, Argentina, 6-3, 6-7 (3), 7-6 (2), 6-2. David Ferrer (18), Spain, lost to Jose Acasuso, Argentina, 6-3, 3-6, 1-6, 6-3, 6-2. Juan Carlos Ferrero (24), Spain, def. Philipp Petzschner, Germany, 1-6, 3-6, 6-4, 6-2, 6-4. Viktor Troicki (30), Serbia, lost to Julien Benneteau, France, 6-1, 3-6, 6-1, 6-0. Nicolas Almagro (32), Spain, def. Robby Ginepri, United States, 6-7 (7), 6-2, 6-3, 4-6, 6-4. Women Third Round Serena Williams (2), United States, def. Maria Jose Martinez Sanchez, Spain, 6-3, 7-5. Venus Williams (3), United States, def. Magdalena Rybarikova, Slovakia, 6-2, 7-5. Vera Zvonareva (7), Russia, def. Elena Vesnina (31), Russia, 6-2, 6-4. Victoria Azarenka (8), Belarus, lost to Francesca Schiavone (26), Italy, 4-6, 6-2, 6-2. Flavia Pennetta (10), Italy, def. Aleksandra Wozniak, Canada, 6-1, 6-1. Li Na (18), China, def. Maria Kirilenko, Russia, 6-4, 6-2. Daniela Hantuchova (22), Slovakia, def. Vania King, United States, 6-2, 6-2. Francesca Schiavone (26), Italy, def. Victoria Azarenka (8), Belarus, 4-6, 6-2, 6-2. Elena Vesnina (31), Russia, def. Vera Zvonareva (7), Russia, 6-2, 6-4. *AP