LONDON (AP) Novak Djokovic will finish the year at the top of the tennis rankings for the third time in four seasons.
Djokovic, who now has an unassailable lead over second-ranked Roger Federer, beat Tomas Berdych 6-2, 6-2 Friday in his final round-robin match at the ATP Finals.
Both Djokovic and Federer have won all three of their matches in London and could meet in Sunday's final.
With Friday's victory, Djokovic extended his indoor winning-streak to 30 matches. He had lost only five games in his first two matches and continued his strong play against Berdych, who dropped his first two service games as the Serb took control from the baseline.
Djokovic again broke twice in the second set to stay unbeaten.