Image:Novak Djokovic had a trophy in his hands on Friday, as his victory secured he would finish the season on top of the world rankings
Image:All eyes were on the Serbian in the afternoon session as he faced off against Tomas Berdych looking to maintain his unbeaten record
Image:Djokovic immediately seized control of the contest, breaking his opponent in his opening two service games as he cruised through the first set
Image:Berdych was unable to mount a response in the second set, meaning he would not be moving on past the round-robin stage
Image:Djokovic, meanwhile, has no such concerns. His 6-2 6-2 triumph means he has now won 30 indoor matches in succession since the World Tour Finals in 2012
Image:The two-time defending champion at the O2 embraces his team after they helped him finish on top of the world for the third year out of the last four
Image:The crowd then got the chance to congratulate Djokovic, who took the time out to sign autographs and pose for selfie!
Image:In the afternoon doubles, Horia Tecau and Jean-Julien Rojer were beaten by Lukasz Kubot of Poland and Robert Lindstedt
Image:Mike Bryan and Bob Bryan of the United States celebrate in style after beating Alexander Peya and Bruno Soares to open up the evening action in the capital
Image:Stan Wawrinka went into the final game of the group stages knowing he needed to win just three games to qualify in second place behind Djokovic
Image:Marin Cilic came into the contest having suffered two defeats - though the Croatian still amazingly had a chance to get through to the last four
Image:X-factor judge Mel B was an interested spectator - nothing spices up your life quite like a trip to watch the tennis at the O2!
Image:Wawrinka wasted little time in securing his qualification from Group A, taking 13 minutes to record a break and set up a showdown with Roger Federer
Image:I wonder who these guys were supporting? Stan was certainly the man in the first set, though he lost the second to Cilic
Image:However the reigning Australian Open champion came out on top in the decider against this year's winner at Flushing Meadows to triumph 6-3 4-6 6-3