Novak Djokovic and Roger Federer reached the second round while Serena Williams comfortably won her grudge match with Maria Sharapova, 6-1 6-1.
Johanna Konta and Dan Evans kept the British flag flying, but Cameron Norrie and Harriet Dart waved goodbye.
Here, PA looks back at day one and forward to day two at the US Open.
Shot of the day
Federer surprisingly dropped the first set against India’s Sumit Nagal, but class told in the end.
4-6, 6-1, 6-2, 6-4@rogerfederer gets his 40th win of the year after rallying to defeat spirited qualifier Sumit Nagal!#USOpen pic.twitter.com/3LBjNp0hrn
— US Open Tennis (@usopen) August 27, 2019
Shock of the day
Angelique Kerber, the winner here in 2016 and last year’s Wimbledon champ, crashed in three sets to unseeded Kristina Mladenovic.
Stat of the day
Quote of the day
“I have an English trainer. He’s had a fantastic 24 hours of feeding it to us and not letting us forget that result.” – Ashes earache for Aussie Ashleigh Barty
Fallen seeds
Men: Fabio Fognini (11), Guido Pella (19), Taylor Fritz (26)
Women: Angelique Kerber (14), Caroline Garcia (27)
Tuesday’s order of play
Arthur Ashe Stadium:
Naomi Osaka v Anna Blinkova
Thomas Fabbiano v Dominic Thiem
John Millman v Rafael Nadal
Sloane Stephens v Anna Kalinskaya
Louis Armstrong Stadium:
Stefanos Tsitsipas v Andrey Rublev
Simona Halep v Nicole Gibbs
Anastasia Potapova v Cori Gauff
Aryna Sabalenka v Victoria Azarenka
Steve Johnson v Nick Kyrgios
Court 13:
Kyle Edmund v Pablo Andujar
Provided by Press Association Sport