Britain's Andy Murray , the sixth seed, beat Switzerland's Stanislas Wawrinka 6-1 6-3 6-3, and will next play Argentina's Juan Martin del Potro , who defeated Kei Nishikori of Japan 6-3 6-4 6-3.
But a surprise four-set defeat by Switzerland's Stanislas Wawrinka followed in the third round at Flushing Meadows, with the Briton beset by physical issues that he was unable to explain immediately afterwards.
Djokovic is on course to meet defending champion Rafael Nadal in the final after the Spaniard maintained his incredible winning streak in Monte Carlo with a 7-5 6-4 victory over Poland's Stanislas Wawrinka.