French Open Day 6-7

Ana Ivanovic of Serbia tucks away the ball for second service in her match against Sara Errani of Italy at the French Open tennis tournament in Roland Garros stadium in Paris, Friday June 1, 2012. (AP Photo/Christophe Ena)

Ana Ivanovic of Serbia returns in her third round match against Sara Errani of Italy at the French Open tennis tournament in Roland Garros stadium in Paris, Friday June 1, 2012. (AP Photo/Christophe Ena)

USA's Sloane Stephens returns the ball to France's Mathilde Johansson during their third round match in the French Open tennis tournament at the Roland Garros stadium in Paris, Friday, June 1, 2012. (AP Photo/Michel Spingler)

Italy's Sara Errani returns the ball to Serbia's Ana Ivanovic during their third round match in the French Open tennis tournament at the Roland Garros stadium in Paris, Friday, June 1, 2012. Errani won 1 6, 7 5, 6 3. (AP Photo/Christophe Ena)

Russia's Maria Sharapova returns the ball to Japan's Ayumi Morita during their second round match in the French Open tennis tournament at the Roland Garros stadium in Paris, Friday, June 1, 2012. Sharapova won 6 1, 6 1.(AP Photo/David Vincent)

Russia's Svetlana Kuznetsova returns the ball to Poland's Agnieszka Radwanska during their third round match in the French Open tennis tournament at the Roland Garros stadium in Paris, Friday, June 1, 2012. (AP Photo/Michel Spingler)

Poland's Agnieszka Radwanska returns the ball to Russia's Svetlana Kuznetsova during their third round match in the French Open tennis tournament at the Roland Garros stadium in Paris, Friday, June 1, 2012. (AP Photo/Michel Spingler)

Maria Sharapova of Russia prepares to serve in her second round match against Ayumi Morita of Japan at the French Open tennis tournament in Roland Garros stadium in Paris, Friday June 1, 2012. Sharapova won in two sets 6 1, 6 1. (AP Photo/Christophe Ena)

Russia's Maria Sharapova blows a kiss to the public after defeating Japan's Ayumi Morita during their second round match in the French Open tennis tournament at the Roland Garros stadium in Paris, Friday, June 1, 2012. Sharapova won 6 1, 6 1.(AP Photo/David Vincent)

Tomas Berdych of the Czech Republic returns in his third round match against Kevin Anderson of South Africa at the French Open tennis tournament in Roland Garros stadium in Paris, Friday June 1, 2012. Berdych won in five sets 4 6, 6 3, 7 6, 4 6, 6 4. (AP Photo/Bernat Armangue)

Croatia's Petra Martic returns the ball to Spain's Anabel Medina Garrigues during their third round match in the French Open tennis tournament at the Roland Garros stadium in Paris, Friday, June 1, 2012. (AP Photo/Michel Euler)

Spain's Anabel Medina Garrigues is being treated by an unidentified medic as she plays Croatia's Petra Martic during their third round match in the French Open tennis tournament at the Roland Garros stadium in Paris, Friday, June 1, 2012. (AP Photo/Michel Euler)

Tomas Berdych of the Czech Republic celebrates winning his third round match against Kevin Anderson of South Africa at the French Open tennis tournament in Roland Garros stadium in Paris, Friday June 1, 2012. Berdych won in five sets 4 6, 6 3, 7 6, 4 6, 6 4. (AP Photo/Bernat Armangue)

Italy's Fabio Fognini returns the ball to France's Jo Wilfried Tsonga during their third round match in the French Open tennis tournament at the Roland Garros stadium in Paris, Friday, June 1, 2012. (AP Photo/Michel Spingler)

A spectator watches France's Jo Wilfried Tsonga playing Italy's Fabio Fognini during their third round match in the French Open tennis tournament at the Roland Garros stadium in Paris, Friday, June 1, 2012. (AP Photo/Michel Spingler)

France's Jo Wilfried Tsonga returns the ball to Italy's Fabio Fognini during their third round match in the French Open tennis tournament at the Roland Garros stadium in Paris, Friday, June 1, 2012. (AP Photo/Michel Spingler)

Jo Wilfried Tsonga of France celebrates winning his third round match against Fabio Fognini of Italy at the French Open tennis tournament in Roland Garros stadium in Paris, Friday June 1, 2012. Tsonga won in three sets 7 5, 6 4, 6 4. (AP Photo/Michel Spingler)

Roger Federer of Switzerland serves in his third round match against Nicolas Mahut of France at the French Open tennis tournament in Roland Garros stadium in Paris, Friday June 1, 2012. (AP Photo/Michel Spingler)

Roger Federer of Switzerland returns in his third round match against Nicolas Mahut of France at the French Open tennis tournament in Roland Garros stadium in Paris, Friday June 1, 2012. (AP Photo/Michel Spingler)

Roger Federer of Switzerland returns in his third round match against Nicolas Mahut of France at the French Open tennis tournament in Roland Garros stadium in Paris, Friday June 1, 2012. (AP Photo/Michel Spingler)

Italy's Andreas Seppi thumbs up after defeating Spain's Fernando Verdasco during their third round match in the French Open tennis tournament at the Roland Garros stadium in Paris, Friday, June 1, 2012. (AP Photo/Michel Euler)

Argentina's Juan Martin del Potro waves to the audience after defeating Croatia's Marin Cilic during their third round match in the French Open tennis tournament at the Roland Garros stadium in Paris, Friday, June 1, 2012. (AP Photo/Bernat Armangue)

Roger Federer of Switzerland, left, and Nicolas Mahut of France, right, are framed through the stairs of the umpire's chair after the third round match at the French Open tennis tournament in Roland Garros stadium in Paris, Friday June 1, 2012. Federer won in four sets 6 3, 4 6, 6 2, 7 5. (AP Photo/Michel Spingler)

Germany's Angelique Kerber serves the ball to Italy's Flavia Pennetta during their third round match in the French Open tennis tournament at the Roland Garros stadium in Paris, Friday, June 1, 2012. (AP Photo/Bernat Armangue)

Roger Federer of Switzerland wipes his forehead after his third round match against Nicolas Mahut of France at the French Open tennis tournament in Roland Garros stadium in Paris, Friday June 1, 2012. Federer won in four sets 6 3, 4 6, 6 2, 7 5. (AP Photo/Michel Spingler)

Novak Djokovic of Serbia returns in his third round match against Nicolas Devilder of France at the French Open tennis tournament in Roland Garros stadium in Paris, Friday June 1, 2012. (AP Photo/Christophe Ena)

Novak Djokovic of Serbia returns in his third round match against Nicolas Devilder of France at the French Open tennis tournament in Roland Garros stadium in Paris, Friday June 1, 2012. (AP Photo/Christophe Ena)

Novak Djokovic of Serbia serves in his third round match against Nicolas Devilder of France at the French Open tennis tournament in Roland Garros stadium in Paris, Friday June 1, 2012. (AP Photo/Christophe Ena)

Serbia's Novak Djokovic thumbs up after defeating France's Nicolas Devilder during their third round match in the French Open tennis tournament at the Roland Garros stadium in Paris, Friday, June 1, 2012. (AP Photo/Christophe Ena)

Victoria Azerenka of Belarus returns in her third round match against Aleksandra Wozniack of Canada at the French Open tennis tournament in Roland Garros stadium in Paris, Friday June 1, 2012. Azarenka won in two sets 6 4, 6 4. (AP Photo/Michel Euler)

Yaroslova Shvedova of Kazakhstan returns in her third round match against Carla Suarez Navarro of Spain at the French Open tennis tournament in Roland Garros stadium in Paris, Saturday June 2, 2012. (AP Photo/Michel Spingler)

Russia's Nina Bratchikova returns the ball to Czech Republic's Petra Kvitova during their third round match in the French Open tennis tournament at the Roland Garros stadium in Paris, Saturday, June 2, 2012. (AP Photo/Christophe Ena)

Francesca Schiavone of Italy screams after marking a point in her third round match against Varvara Lepchenko of the U.S. at the French Open tennis tournament in Roland Garros stadium in Paris, Saturday June 2, 2012. (AP Photo/Michel Euler)

Czech Republic's Petra Kvitova returns the ball to Russia's Nina Bratchikova during their third round match in the French Open tennis tournament at the Roland Garros stadium in Paris, Saturday, June 2, 2012. (AP Photo/Christophe Ena)

Petra Kvitova of the Czech Republic celebrates winning her third round match in three sets 6 2, 4 6, 6 1, against Nina Bratchikova of Russia at the French Open tennis tournament in Roland Garros stadium in Paris, Saturday June 2, 2012. (AP Photo/Christophe Ena)

Spain's David Ferrer reacts as he defeats Russia's Mikhail Youzhny during their third round match in the French Open tennis tournament at the Roland Garros stadium in Paris, Saturday, June 2, 2012. (AP Photo/Bernat Armangue)

Spain's David Ferrer returns the ball to Russia's Mikhail Youzhny during their third round match in the French Open tennis tournament at the Roland Garros stadium in Paris, Saturday, June 2, 2012. (AP Photo/Bernat Armangue)

Russia's Mikhail Youzhny serves to Spain's David Ferrer during their third round match in the French Open tennis tournament at the Roland Garros stadium in Paris, Saturday, June 2, 2012. (AP Photo/Bernat Armangue)

Yaroslova Shvedova of Kazakhstan celebrates winning her third round match against Carla Suarez Navarro of Spain at the French Open tennis tournament in Roland Garros stadium in Paris, Saturday June 2, 2012. (AP Photo/Michel Spingler)

Italy's Francesca Schiavone reaches for the ball as she plays USA's Varvara Lepchenko during their third round match in the French Open tennis tournament at the Roland Garros stadium in Paris, Saturday, June 2, 2012. (AP Photo/Michel Euler)

Li Na of China serves in her third round match against Christina McHale of the U.S. at the French Open tennis tournament in Roland Garros stadium in Paris, Saturday June 2, 2012. (AP Photo/Bernat Armangue)

Christina McHale of the U.S. returns in her third round match against Li Na of China at the French Open tennis tournament in Roland Garros stadium in Paris, Saturday June 2, 2012. (AP Photo/Bernat Armangue)

Varvara Lepchenko of the U.S. celebrates winning her third round match against Francesca Schiavone of Italy at the French Open tennis tournament in Roland Garros stadium in Paris, Saturday June 2, 2012. Lepchenko won in three sets 3 6, 6 3, 8 6. (AP Photo/Michel Euler)