Roger Federer has lost his opening group match at the ATP Finals in London this evening to Japan’s Kei Nishikori. Federer chasing a 100th career title at the end of season tournament, lost in straight sets 7-6 6-4 to the world number nine. Earlier this afternoon big serving South African and current world number six Kevin Anderson made a superb start to his ATP Finals beating Dominic Thiem 6-3 7-6. The world number one Novak Djokovic opens his campaign tomorrow evening against American John Isner.