World number one Novak Djokovic has cruised into the quarter-finals of the US Open with a straight-sets win over Marcel Granollers.

The Serb was in imperious form from the off as he dominated the 27-year-old mixing up his strokes nicely as he broke the Spaniard to claim the first set 6-3.

Djokovic upped the ante in the second as he continued to baffle Granollers with his use of spin across the court. His return skills improved as well as he overpowered the unseeded Spaniard, breaking three times to take the set 6-0.

The number one seed was all over the 27-year-old in the third as he had no answer for the Serb, as Djokovic hit 13 winners on the way to clinching the set 6-0 in just 21 minutes.

Djokovic will now face Mikhail Youzhny in the quarter-finals.