Rafael Nadal of Spain reacts after a point against Novak Djokovic of Serbia during the men's singles final of the 2013 U.S. Open tennis tournament Monday in New York. Charles Krupa/AP hide caption

Andy Murray broke Britain's more than seven-decade men's title drought Sunday, beating top seed Novak Djokovic in straight sets. Anja Niedringhaus/AP hide caption

Serbia's Novak Djokovic (left) embraces Argentina's Juan Martin Del Potro after their match on day 11 of the 2013 Championships at Wimbledon. Carl Court/AFP/Getty Images hide caption

Roger Federer of Switzerland celebrates match point during his match today against Novak Djokovic of Serbia at the Wimbledon Lawn Tennis Championships. Clive Rose/Getty Images hide caption

Rafael Nadal of Spain celebrates winning the French Open earlier today. Bernat Armangue/AP hide caption