It's day two of the fourth grand slam of the year.
The 4th, 6th and 7th seeds in the mens singles are all in action today at the US Open in New York.
Alexander Zverev is up against Sam Querrey of the United States.
Mateo Berrettini meets Frenchman Jeremy Chardy and Canadian Denis Shapovalov faces Federico Delbonis.
As for last night's action on the court, Japan's Naomi Osaka won her first Grand Slam match since pulling out of the French Open.
She defeated Czech player Marie Bouzkova 6-4, 6-1 in the first round.
Later on today, top seed Ashleigh Barty will meet Vera Zvonareva.
Andy Murray has been knocked out of the men's singles.
He went down in five sets to Stefanos Tsitsipas having been 2 sets to 1 ahead.