Former champion Daniil Medvedev reached his fifth US Open quarter-final in six years on Monday with a straight-sets victory over unseeded Nuno Borges.

Medvedev, the 2021 winner in New York, outclassed Borges, who was bidding to become the first Portuguese man to make a Grand Slam quarter-final, 6-0, 6-1, 6-3.

Russia's Medvedev will meet Jannik Sinner for a place in the semi-finals if the world number one Italian defeats Tommy Paul of the United States in his last-16 clash in the night session on Arthur Ashe Stadium.

"I played Tommy twice this season. I beat him once but I feel as if he should have beaten me both times," said Medvedev.

"I've had unbelievable battles with Jannik. It will be very physical for both of us."

Medvedev is the only former champion left in the tournament after the shock exits of Novak Djokovic and Carlos Alcaraz. (AFP)