LONDON Durham Smythe Youth Jersey , Nov. 9 (Xinhua) -- Sixth seed and six-time former champion Roger Federer battled back from a 0-3 deficit in the third set to beat fourth seed and 2009 runner-up Juan Martin del Potro to reach the semifinals at the ATP World Tour Finals here on Saturday.
The Swiss former No. 1 won 4-6, 7-6 (2), 7-5 to finish in second position in Group B for a clash against top seed and 2010 finalist Rafael Nadal on Sunday.
Second seed Novak Djokovic of Serbia, who had already qualified Jason Sanders Youth Jersey , beat Frenchman Richard Gasquet 7-6, 4-6, 6-3 in the other match to top Group B. The reigning champion will next face seventh seed Stanislas Wawrinka of Switzerland in the semifinals.
Nadal leads Federer 21-10 in their previous meetings and has won their past three matches.