World number one Novak Djokovic began his US Open campaign with victory over Poland’s Jerzy Janowicz – despite the Serb requiring treatment to his arm.
Djokovic, who has struggled with a wrist injury, won 6-3 5-7 6-2 6-1 after calling the trainer in the first set.
Spanish fourth seed Rafael Nadal beat Uzbekistan’s Denis Istomin 6-1 6-4 6-2.
In the upset of the first round, Kyle Edmund ranked 84th, beat former semi-finalist and 13th seed Richard Gasquet 6-2 6-2 6-3 to claim the best win of his career on a hot afternoon at Flushing Meadows.
Germany’s Angelique Kerber, seeded second in the women’s draw, led Polona Hercog 6-0 1-0 when the Slovenian succumbed to leg cramps.
Meanwhile, world number one women’s seed Serena Williams will be in action this Tuesday taking on unseeded Russian, Ekaterina Makarova.