Day 1: Djokovic v Nishikori

Sue Barker hosts live coverage from the opening day of the ATP World Tour Finals from the O2 Arena in London. The season-ending tournament pits the best eight players in men's tennis against each other in a round-robin format. The top four performers will go through to the semi-finals, with the two winners battling it out in Sunday's final. On the opening day in 2014, Britain's Andy Murray made a disappointing start as he was beaten by Japan's Kei Nishikori in straight sets.

Commentary comes from Andrew Castle and Tim Henman.