World number one Novak Djokovic has booked the last eight berth in the Men's Singles of the US Open, season's final Grand Slam, last night. Serbian Djokovic registered straight set victory in the 3rd round over Germany's Philipp Kohlschreiber, 6-1, 7-5, 6-4.Briton Andy Murray also eased pass through 3rd round against French Jo Wilfired Tsonga in straight sets. 8th seed Murray defeated 9th seed Tsonga 7-5, 7-5, 6-4.In the Women's Singles, World Number one Serena Williams has entered the quarterfinals after defeating unseeded Kaia Kanepi of Estonia 6-3, 6-3. Serena will face Italian Flavia Pennetta in the quarters.