Djokovic moves into semis

It took the Serb nearly an hour to prevail in the first set but he closed out a one-sided tie-break with a deft backhand passing shot. The second was one-way traffic as the World No.1 played with relentless efficiency against an opponent who ran out of answers.

Perhaps the only concern for Djokovic with the US Open looming in less than two weeks was a sore elbow, which required brief treatment by his trainer late in the match.

Daniil Medvedev continued his recent hot form, ousting Russian compatriot Andrey Rublev 6-2, 6-3 in barely an hour. In another last eight clash, Frenchman Richard Gasquet continued his comeback from groin surgery by defeating Spaniard Roberto Bautista Agut 7-6(2), 3-6, 6-2.

World No.1 Naomi Osaka of Japan retired from her Cincinnati Masters quarter-final with an apparent knee injury.

Osaka, who was playing American Sofia Kenin, sought treatment on the knee in the third set and then pulled out. Kenin was ahead 6-4, 1-6, 2-0 at the time. The injury comes less than two weeks before the start of the US Open, where Osaka is the defending champion. Madison Keys trounced American rival Venus Williams in straight sets, winning by a scoreline of 6-2, 6-3.