Novak Djokovic reacts during his tennis match against Tomas Berdych at the ATP World Tour Finals in London...
Novak Djokovic of Serbia reacts during his tennis match against Tomas Berdych of Czech Republic at the ATP World Tour Finals at the O2 Arena in London November 14, 2014. Djokovic added another processional victory to the lengthening list at the ATP World Tour Finals with a 6-2 6-2 demolition of subdued Berdych on Friday. REUTERS/Stefan Wermuth (BRITAIN - Tags: SPORT TENNIS)