Novak Djokovic has set his sights on following his successful defence of the ATP World Tour Finals by leading Serbia to glory in the Davis Cup final. Djokovic won the prestigious season-ending Tour Finals for the third time with a dominant 6-3, 6-4 victory over world number one Rafael Nadal at the O2 Arena in London. The 26-year-old has played some of the best tennis of his life since losing the US Open final against Nadal in September and Monday's win was his 22nd successive match victory -- a run that has brought him titles in Beijing, Shanghai, Paris and now London. But, although Djokovic could be forgiven for wanting a well-earned holiday after such an intense period, the world number two has no time to rest on his laurels because he will now fly to home to Belgrade to prepare for the Davis Cup final clash against holders Czech Republic, which starts on Friday. Serbia last won the Davis Cup in 2010 and Djokovic would dearly love to repeat that triumph. "It's a fact that it's been a very long season for me and I'm exhausted in every way. But God knows if we're going to have as a country another opportunity like this to win a Davis Cup title at home," Djokovic said. "We have very tough opponents, the defending champions, but the Davis Cup is the only team competition in our sport that brings the best possible energy and willpower in me. "I'm going to do my best to recover the next three days and get ready for that one." Once Djokovic has finished with his national service, he will finally be able to put his feet up and reflect on a year that brought him joy and despair in equal measure. After winning the Australian Open for the fourth time in January, he suffered a frustrating semi-final loss to Nadal at the French Open -- the one Grand Slam title he has never won. That was followed by a Wimbledon final defeat against Andy Murray and another painful loss at Nadal's hands in the US Open that eventually led to the Spaniard replacing Djokovic at the top of the world rankings. To a less mentally tough character, those setbacks could have been devastating, but for Djokovic they have simply provided the motivation for his late-season resurgence. "Next to the run that I had in 2011, this is definitely the second best I've had," Djokovic said. "For me, the most positive thing  is the fact that I managed to regroup after a few big losses to Nadal, especially at Roland Garros and the US Open final. "After that I needed to take things slowly and analyse what I did wrong in the matches against him, to understand what I need to do in order to win against him. "I've worked harder and become an even more skillful player. I've worked on a few things in my game and serve. "I think the results are showing that we had a great improvement in the last two and a half months." Nadal will finish the year as the world number one, but Djokovic has won their last two encounters and he is confident of recapturing his position as the sport's preeminent force in 2014. "The year-end number one is deservedly in Nadal's hands because he had two Grand Slam wins, the best season out of all players, the most titles," Djokovic said. "Even though I had an incredible two and a half months since the US Open final, he was the most successful player. "The only thing I'm not as satisfied about is the fact that I lost the three big matches in the three Grand Slams. Djokovic reigned supreme at the ATP World Tour Finals as the defending champion crushed Nadal 6-3, 6-4 in Monday's final. "This can serve as a great platform for 2014 season. I'm extra motivated and inspired to work on my game and get ready for the Australian Open" in January, he said. Source: AFP