London: Novak Djokovic stayed perfect at the ATP finals, beating Tomas Berdych 6-2, 7-6 (6) Friday and qualifying for the semi-finals of the season-ending event. Djokovic is 3-0 in Group A and will play Sunday for a spot in Monday's final. The other semifinalist from the group will be decided later Friday when Andy Murray takes on Jo-Wilfried Tsonga.
Djokovic, who reclaimed the No. 1 ranking at the beginning of the week, had little trouble against Berdych. He broke his Czech opponent twice in the first set and once in the second, though he was broken right back on the third occasion to force the tiebreaker.
The ATP finals is the last tournament of the season, and only for the top eight players in the world.