Image:World number one Novak Djokovic walked out on court to take on Juan Martin Del Potro in the first semi-final of the ATP World Tour Finals in London.
Image:Del Potro used his forehand well to take the opening set
Image:However, Djokovic hit back to send the match into a decider
Image:Djokovic stepped up a gear in the final set as he moved to the brink of victory
Image:Del Potro's body language suggested he knew the writing was on the walls
Image:The Serbian soon polished off a 4-6 6-3 6-2 victory to advance to the final against either Andy Murray or Roger Federer
Image:India's Mahesh Bhupathi and Rohan Bopanna won the first doubles semi-final
Image:Jonny Marray and Freddie Nielsen were looking to join them in the final
Image:But it was Spanish duo Marc Lopez and Marcel Granollers who triumphed
Image:Andy Murray walked out on court to take on Roger Federer in the semi-final
Image:The British number one broke early on
Image:But Federer hit back in what was becoming a tightly-contested opening set
Image:And it was the Swiss ace who edged it on a tie-break
Image:Murray shows his frustration as his opponent took control
Image:Federer stormed through the second set, taking it 6-2 to book his place in the final
