World number two Daniil Medvedev is through to the third round of the US Open following a comfortable 6-4 6-1 6-2 victory over Dominik Koepfer.

The Russian second seed hit eight aces and won 80% of points on his first serve in a commanding performance under the roof on Arthur Ashe Stadium.

He faces Spaniard Pablo Andujar in the third round.

Meanwhile, Russian fifth seed Andrey Rublev beat Spaniard Pedro Martinez 7-6 (7-2) 6-7 (5-7) 6-1 6-1 to set up a third-round meeting with American Frances Tiafoe.

In front of a noisy home crowd on Louis Armstrong Stadium, 23-year-old Tiafoe played superbly to win 6-1 6-2 7-5 against Argentina's Guido Pella and set up a first senior meeting with Rublev.

Canadian 12th seed Felix Auger-Aliassime advanced with a 7-6 (7-5) 6-3 6-2 win over Spain's Bernabe Zapata Miralles.

Spanish teenager Carlos Alcaraz again demonstrated why he is one of the sport's most-talked about young stars by beating France's Arthur Rinderknech in four sets.

Alcaraz, 18, is youngest man to reach the third round in two Grand Slams since 20-time major champion Novak Djokovic in 2005.

There was an upset when eighth seed Casper Ruud was knocked out by Dutch world number 117 Botic van de Zandschulp, who beat the Norwegian 3-6 6-4 6-3 6-4 to reach the third round of a Grand Slam for the first time.

Meanwhile, Bulgarian 15th seed Grigor Dimitrov retired while trailing by two sets and a double break against Australian Alexei Popyrin.

Popyrin plays Dan Evans in the third round after the British number one equalled his best performance at the US Open to beat American Marcos Giron 6-4 7-6 (7-3) 2-6 6-3.