Monday's action at the U.S. Open
A photographic look at grand slam matches from the Billie Jean King tennis center
Jo-Wilfried Tsonga of France celebrates after defeating Mardy Fish of the United States during Day Eight of the 2011 US Open at the USTA Billie Jean King National Tennis Center on September 5, 2011 in the Flushing neighborhood of the Queens borough of New York City. (Photo by Nick Laham/Getty Images)Nick Laham/Getty Images
Janko Tipsarevic of Serbia falls to the court after returning a shot from Juan Carlos Ferrero of Spain. Tipsarevic advanced with a 7-5, 6-7 (3), 7-5, 6-2 victory. REUTERS/Jessica RinaldiJessica Rinaldi/Reuters
Tennis patrons look out over an evening sky from their seats. REUTERS/Jessica RinaldiJessica Rinaldi/Reuters
Novak Djokovic of Serbia reacts after winning the first set during his match against Alexandr Dolgopolov of the Ukraine. Djokovic won 7-6 (14), 6-4, 6-2. (AP Photo/Paul J. Bereswill)Paul J. Bereswill/The Associated Press
Number one seed Novak Djokovic of Serbia reacts after winning the first set tiebreak 16-14 against Alexandr Dolgopolov of Ukraine during a Men's fourth round match at the US Open tennis tournament on September 5, 2011 at the Billie Jean King National Tennis Center in New York. Getty Images/Stan HONDAStan HONDA/Getty Images
Andrea Petkovic of Germany plays with a ball in her shorts as she volleys from serve to Carla Suarez Navarro of Spain. Petkovic advanced with a 6-1, 6-4 win. REUTERS/Jessica RinaldiJessica Rinaldi/Reuters
Actress Blake Lively (L) watches as Serena Williams of the United States plays against Ana Ivanovic of Serbia during. (Photo by Mike Stobe/Getty Images for USTA)Mike Stobe/Getty Images
Mardy Fish of the U.S. lies on the court after slipping while returning a shot to Jo-Wilfried Tsonga of France during their match at the U.S. Open tennis tournament in New York, September 5, 2011. REUTERS/Eduardo MunozEduardo Munoz/Reuters
Roger Federer, of Switzerland, returns to Juan Monaco, of Argentina, in the fourth round of the U.S. Open tennis tournament, Tuesday, Sept. 6, 2011, in New York. Federer won 6-1, 6-2, 6-0. (AP Photo/Elise Amendola)Elise Amendola/The Associated Press
Caroline Wozniacki, of Denmark, reacts during her match against Svetlana Kuznetsova, of Russia. Wozniacki won 6-7(6) 7-5 6-1. (AP Photo/Elise Amendola)Elise Amendola/The Associated Press