Day 5: Djokovic v Berdych

Sue Barker is at the O2 Arena in London to present further live coverage of the ATP World Tour Finals as Tomas Berdych faces reigning world number one Novak Djokovic. It's the first season since 2003 that there have been four different winners of the men's Grand Slam singles titles, so competition is sure to be fierce as the world's top players do battle for the final time in 2012.