London calling for Djokovic
Defending champion Novak Djokovic has become the second player to qualify for this year's Barclays ATP World Tour Finals in London.
The world number one is guaranteed to finish the season as one of the world's top eight following his run to the quarter-finals in Cincinnati last week.
It is the seventh year in a row that the Serb has qualified for the season-ending finale. As well as emerging victorious last season, he also won the event in 2008 when it was held in Shanghai.
He joins Rafael Nadal in the field for the event at the O2 Arena which takes place from November 4-11.
"(Being defending champion) adds a little bit of extra expectation and pressure," said Djokovic.
"Knowing that I can play that well on the centre stage gives me enough reason to believe that I can do it again. That is something that inspires me to prepare well and perform my best."
Six places remain up for grabs with Wimbledon champion Andy Murray currently leading the chase. He is virtually guaranteed a spot.
However, Roger Federer is just seventh in the points race and is far from certain of returning to London.