World Number one Novak Djokovic has targeted a hat-trick of ATP World Tour Finals wins after an impressive season on the indoor courts.

The two-time Tour Finals winner is on a 27-match unbeaten run on the indoor circuit after successfully retaining his Paris Masters title last week, in a 6-2 6-3 win over Milos Raonic.

The 27-year-old Serb told atpworldtour.com: “It definitely encourages me the fact that I have played so well, and that I have won the past four indoor tournaments in the past two years that I’ve played.

“From outdoor hard court that was my most successful and most preferred surface, now I guess it’s an indoor court. I do feel very comfortable playing, returning, serving in these conditions.”

The event at the O2 Arena in London, which gets underway on Sunday, sees the world’s best tennis stars come up against each other, and Britain’s Andy Murray will play Kei Nishikori to get the tournament underway.

Djokovic will have to wait until the evening session on Monday to play his first match, which sees him come up against Marin Cilic.

The Serb has beaten Croatia’s US Open champion Cilic on all of their previous ten meetings, and says he’s looking forward to playing in the English capital.

“I’m excited to be there, because I think it’s one of the most spectacular tennis venues that we have. People in London love tennis and have appreciation for this sport. So I look forward to that.”