Nadal advances

Rafael Nadal held off Tomas Berdych 6-4, 1-6, 6-3 to finish the round robin 3-0 and win his group Friday at the ATP World Tour Finals in London, allowing Stanislas Wawrinka to join him in the last four. Wawrinka beat David Ferrer 6-7 (3), 6-4, 6-1, but needed Nadal to win to advance to the semifinal. Nadal lost his grip on the match in the second set, dropping his serve twice. The Spaniard had already qualified from Group A after winning his first two matches, clinching the year-end No. 1 ranking the process. Nadal only needed to claim a set against Berdych to clinch the group victory. But he broke Berdych in the eighth game of the third set after Berdych double-faulted twice. Against Ferrer, Wawrinka hit 35 winners, including 12 aces, to clinch his second victory at the season-ending tournament. Defending champion Novak Djokovic has won Group B. The winner of today’s match between Juan Martin del Potro and Roger Federer will join him in the semifinals.