Stefanos Tsitsipas motors into second round past Albert Ramos-Vinolas

Fourth seed Stefanos Tsitsipas rolled into the second round with a dominant 6-2, 6-1, 6-1 victory over Spain's Albert Ramos-Vinolas.

He served 13 aces, faced no break points and won the last six games on the spin to close out the match.

"I had a clear picture of what I was doing, where I was pressing. The depth on my ball was good," said Tsitsipas, whose best Grand Slam result to date came at the 2019 Australian Open where he reached the semi-finals.

The 22-year-old Tsitsipas, who has never been beyond the second round in Flushing Meadows, came into this week with 16 wins to his name this season and has been tipped by many to make a deep run in a tournament missing a number of top players.

He will next face the American wildcard Maxime Cressy, who beat Slovakian Jozef Kovalik 6-1, 2-6, 6-4, 6-4.

Germany's Alexander Zverev survived a tricky first-round test to beat 2017 finalist Kevin Anderson 7-6(2) 5-7 6-3 7-5 in the U.S. Open on Monday.

For the second straight event since the COVID-19 lockdown, world number seven Zverev was given a tough draw, facing a former top-five opponent in his opening match.

"Kevin is not somebody you usually play in the first round," the 23-year-old Zverev said.

After losing to Andy Murray at the Western and Southern Open last week, Zverev ensured he came out of the blocks quickly against Anderson and he took the opening set in a one-sided tiebreak.

Both players were locked in an intense serve-and-volley duel before Anderson converted his only break-point opportunity in the second set.

The 2.03-metre tall South African came out on top with some deft touches at the net to draw level after two sets but Zverev soon found another gear to regain momentum.

Fifth seed Zverev took control of the contest with an early break in the third set as Anderson, playing only his ninth match of another injury-plagued season, struggled to keep up with his opponent's stinging groundstrokes.

After showing impressive control on his first serve, Zverev patiently worked on Anderson's serve to carve out a decisive break point late in the fourth set to clinch a hard-fought victory.

The result gave Zverev a much-needed confidence boost as he bids to improve on his maiden Grand Slam semi-final appearance in Melbourne earlier this year.

Zverev will next face American wild card Brandon Nakashima, who defeated Italian Paolo Lorenzi 6-3 6-2 7-6(3)