London: World No. 1 Rafael Nadal defeated Tomas Berdych for the 16th straight time to qualify for the semi-finals from Group A with a perfect 3-0 record at the ATP World Tour Finals here Friday.
Nadal, who had already sealed his berth, helped seventh seed Stanislas Wawrinka of Switerland to qualify for the semi-finals. Berdych needed to beat Nadal to ensure his spot in the last four, reported Xinhua. (Read: Wawrinka beats tired Ferrer)
"Stan came to the locker room and said good luck. I said I would try my best. It's a good result for Stan. He's good friend of mine," said Nadal.