Belgium's Kim Clijsters celebrates her victory over Serbia's Jelena Jokovic

Stewards lead people into the All England Lawn Tennis and Croquet Club

Security walk the crowd in during day one of the 2012 Wimbledon Championships at the All England Lawn Tennis Club, Wimbledon.

Spain's Rafael Nadal during practice on day one of the 2012 Wimbledon Championships at the All England Lawn Tennis Club, Wimbledon.

Great Britain's Josh Goodall celebrates against Slovenia's Grega Zemlja during day one of the 2012 Wimbledon Championships at the All England Lawn Tennis Club, Wimbledon.

Serbia's Novak Djokovic in action against Spain's Juan Carlos Ferrero during day one of the 2012 Wimbledon Championships at the All England Lawn Tennis Club, Wimbledon.

Argentina's David Nalbandian reacts in his match against Serbia's Janko Tipsaravic during day one of the 2012 Wimbledon Championships at the All England Lawn Tennis Club, Wimbledon.

Colombia's Alejandro Falla celebrates against USA's John Isner during day one of the 2012 Wimbledon Championships at the All England Lawn Tennis Club, Wimbledon.

Slovakia's Daniela Hantuchova in action against USA's Jamie Lee Hampton during day one of the 2012 Wimbledon Championships at the All England Lawn Tennis Club, Wimbledon.

Serbia's Jelena Jokovic sits dejected after losing to Belgium's Kim Clijsters

Russia's Vera Zvonareva in action against Germany's Mona Barthel during day one of the 2012 Wimbledon Championships at the All England Lawn Tennis Club, Wimbledon.

Italy's Flavia Pennetta in action against compatriot Camila Giorgi

Serbia's Novak Djokovic in action against Spain's Juan Carlos Ferrero during day one of the 2012 Wimbledon Championships at the All England Lawn Tennis Club, Wimbledon.

Serbia's Novak Djokovic in action against Spain's Juan Carlos Ferrero

Serbia's Janko Tipsaravic celebrates victory over Argentina's David Nalbandian

Switzerland's Roger Federer warms up against Spain's Albert Ramos