Djokovic digs deep to find final answer to the Federer question Their season has raged for 10 and a half months but Novak Djokovic and Roger Federer saved some of their very best for last. The world's two top-ranked players brought the curtain down on a memorable year on the men's circuit here last night by staging a stunning climax to the Barclays ATP World Tour Finals. After a year in which the game's top four players have won almost every major prize, it was only fitting that the final honour went to the world No 1 as Djokovic beat Federer 7-6, 7-5 in a thriller that lasted two and a quarter hours. Much of the tennis was sensational as the two men traded hammer-blow punches and retrieved balls from apparently impossible positions. Djokovic in particular seemed to defy all physical logic with the way he slid into his shots - an extraordinary ability on a hard court - and found the power to hit winners when most mortals would have been relieved simply to play defensive lobs. The 25-year-old Serb, who had to have treatment to a cut on his arm after diving to play one shot towards the end of the first set, has taken athleticism in tennis to another dimension. Federer, meanwhile, continues to hold back the years. The 31-year-old Swiss has finished the season looking as lithe and graceful as ever and you write him off at your peril. Despite failing in his attempt to win this tournament for a seventh time, he has had his most successful season in terms of match wins (71) since 2006. His tally of six titles - which included his 17th Grand Slam crown - is his best return in a year since 2007. Djokovic will probably never match the year he had in 2011, when he won three Grand Slam tournaments and seven other titles, but, considering the challenge he faced in living up to those exploits, his follow-up season has been every bit as admirable. He has won six titles and his total of 75 match wins is more than any other player has managed this year. In the 43-year history of the tournament this was only the fourth occasion when the world's top two players had met in the final. Djokovic is the only member of the game's Fab Four who has lost more matches (16) against Federer than he has won (13) - Rafael Nadal leads 18-10 in his head-to-head record with the Swiss while Andy Murray leads 10-9 - though the Serb has started to turn the tables in the last three years. Federer, nevertheless, had won their two most recent encounters, in this summer's semi-finals at Wimbledon and Cincinnati final. A tight contest hardly seemed on the cards when Djokovic lost the first nine points of the match, the Federer express coming to a halt only when the Swiss put a forehand wide. Going for his shots like a man possessed, Federer went 3-0 up, but Djokovic quickly worked his way into the match to level at 3-3. For the rest of the opening set it was the Serb who set the pace. Federer was broken again at 4-4, Djokovic creating his third and final break point of the game with a stunning shot as he struck a winning forehand cross-court pass despite being off-balance. Federer served well throughout, but Djokovic kept responding with breathtaking returns. Federer saved a set point when breaking back in the following game and had the crowd on their feet in the tie-break when he saved another with a forehand cross-court winner off a ball that had all but flown beyond his reach. Two points later, however, Djokovic took the tie-break 8-6 with a beautifully angled inside-out forehand. Losing a 72-minute first set had not exactly been in the older man's game plan, but Federer was undeterred. The Swiss broke immediately on the resumption and held the advantage until he failed to serve out for the second set at 5-4, just as Djokovic had in the opener. The fire was now in Djokovic's eyes and the Serb played the next two games as if his life depended on it. On his first match point he thumped a superb backhand down the line which Federer was unable to return. "It was a great match," Federer said afterwards, refusing to be downcast about his defeat. I think I played very well. It was extremely close. swiss support federer favourite If Andy Murray's fans were disappointed that Roger Federer enjoyed such widespread support among the crowd in the O2 Arena on Sunday night it was a reminder of what a challenge the sport will face when the 31-year-old Swiss eventually retires. Murray might have expected more support in the wake of the Olympics, when the home crowd got behind him more than any previous occasion, but the backing for Federer was similar to that he has enjoyed in all his previous meetings with Murray on British soil. Murray was not surprised. "When you play Roger anywhere in the world, he gets great support," the Scot said.