Swiss world No. 1 Roger Federer stuttered past his compatriot Stanislas Wawrinka into the quarterfinals of the Shanghai Masters on Thursday.

The 31-year-old Federer 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.

This success marks another milestone in the career of the Swiss legend, 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 Vardasco 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 6-2, 6-1.

The German veteran will now face another Serbian star Novak Djokovic in the quarters.