The irrepressible form of world number two Novak Djokovic has resulted in him becoming the first player to qualify for the season ending 2011 ATP World Tour Finals.

On Sunday, his 6-4 6-4 win against world number one Rafael Nadal in the Rome Masters final, extended his unbeaten run in 2011 to 37 matches, making him only the second man after Nadal in 2009 to qualify for the World finals before the French Open.

The finals features the world's top eight players, all of whom will battle it out at London's O2 Arena by the end of November. Last season, Roger Federer won the tournament, beating Djokovic in the semifinals. Incidentally, the Serb hasn't lost since. After winning two matches in the Davis Cup after the season-ending tournament, the Serb carried on his form through the year, winning the Australian Open as well as in Dubai, Indian Wells, Miami, Belgrade, Madrid and Rome.

It will be the fifth successive time the 23-year-old has qualified for the tournament.

After his triumph in Italy, Djokovic said, Everything started from the Davis Cup. I did make some changes but all these years I've been in a learning process, working hard and waiting one day for everything to come together and all the work to pay off.

I was winning major events before but I didn't have this consistency or the right mental approach against the big players. I was losing a lot in Grand Slams and Masters against Rafa and Roger, I didn't have the confidence.

The Davis Cup gave me incredible energy and I'm definitely not thinking about losing matches, I'm just thinking about winning.