Full replay from Wimbledon as Roger Federer (SUI) takes on Juan Martin Del Potro (ARG) in the semi-final of the men's singles tennis event at the London 2012 Olympic Games (3 August 2012). Subscribe to the Olympic channel: http://bit.ly/1dn6AV5 Tennis has a long Olympic history but withdrew from the programme after 1924. It did not return as a medal sport until 1988. Professionals are now welcome to compete, and the Olympic competition includes men's and women's singles and men's and women's doubles. Find more about Tennis at http://www.olympic.org/tennis