The world's best tennis players show their intensity on the clay courts at Roland Garros during the 2013 French Open in Paris.
American Jack Sock hits a shot during his French Open men's first round match against Spaniard Guillermo Garcia-Lopez at Roland Garros in Paris on May 28, 2013. Sock defeated Garcia-Lopez 6-2, 6-2, 7-5. UPI/David Silpa