Shanghai, Oct 12 : Swiss world No. 1 Roger Federer stuttered past his compatriot Stanislas Wawrinka into the quarterfinals of the Shanghai Masters.
Federer, 31, dropped the first set before surging back in the second to crush the 13th seed in the decider for a 4-6, 7-6(4), 6-0 win Thursday.
This success marks another milestone in the career of the Swiss maestro, guaranteeing him a 300th week at the top of ATP rankings, an all-time record.
The next opponent of Federer will be Marin Cilic, who eliminated Spain's Fernando Verdasco in three sets.
The Croatian 10th seed also had to recover from a set down and secured a 4-6, 6-1, 6-4 victory.
Elsewhere, sixth seed Janko Tipsarevic was stunned by world No. 21 Tommy Haas 2-6, 1-6.
The German veteran will now face another Serbian star Novak Djokovic in the quarters.