World number one Novak Djokovic has become the first player to win the season-ending ATP World Tour Finals for the fourth consecutive time. In the title clash played in London last night, Djokovic defeated third seed Roger Federer, in straight sets, 6-3, 6-4 to cap a remarkable season, and surpass Ivan Lendl's 1987 feat, when he had won his third straight Tour Finals title. Overall, this was the fifth time that Djokovic won this tournament. He ends the year with 11 titles, including three Grand Slams, taking his total to 10 majors. Federer had defeated Djokovic in the round-robin stage, but the world number one Serb made sure that he drew level with Federer in 44 career meetings, with both players now winning 22 games each. The defeat for the Swiss also means that he will not be overtaking Andy Murray in the rankings, and the Briton will end the year as world number two for the first time.Meanwhile, in the Doubles, the eighth seeded Indo-Romanian team of Rohan Bopanna and Florin Mergea has ended as runner up. They lost to the second seeded Dutch-Romanian team of Jean-Julien Rojer and Horia Tecau, 6-4, 6-3. Bopanna was appearing in his second season-end Finale, having reached the final with Mahesh Bhupathi in 2012.