WASHINGTON - World No 1 Novak Djokovic defeated Pablo Carreno Busta of the United States 6-3, 6-4 to reach the quarterfinals of the ATP Cincinnati Masters on Thursday.

Being the only top-five seed remaining in the US Open tuneup event after the exit of No 3 Roger Federer, the Serbian tennis ace is playing his first tournament after triumphing over Federer in the Wimbledon final last month.

This was Djokovic's third straight win over the fourth seeded Busta, and there are still three victories left to go before he can claim his career golden masters.