World No 1 Novak Djokovic of Serbia overcame the first-set disappointment to deny world No. 99 Jenson Brooksby a place in the US Open quarterfinal with a 1-6, 6-3, 6-2, 6-2 victory over the American in two hours and 58 minutes at Flushing Meadows here.

Djokovic extended his unbeaten ATP head-to-head against Americans at their home Slam to 11-0 and his winning streak against Americans overall to 21. The Serb, who has won all three majors this year -- Australian Open, French Open and Wimbledon -- is just nine more sets away from completing the calendar-year Grand Slam. In a rematch of the Wimbledon final, Djokovic will next meet sixth seed Matteo Berrettini of Italy. The Italian earlier defeated German qualifier Oscar Otte in four sets.