Carlos Alcaraz played down concerns over a knee problem after racing through to the fourth round of the US Open.

The Spaniard called for the trainer late in the second set of his clash with Italy’s Luciano Darderi but then did not lose a single game, wrapping up a 6-2 6-4 6-0 victory in just an hour and 44 minutes.

Alcaraz took a medical timeout, with the trainer massaging his thigh, but showed no ill effects thereafter, and said: “I am feeling good.

“I just felt something that is not working good in the knee but after five, six points it was gone. I just called the physio as a precaution. I’m not worried about it.”

Alcaraz’s biggest concern ahead of the match was an unusually early start time for him of 11.30am – a big change from his previous two matches, which were in the night session.

“I just tried to start awake,” he said with a smile. “It’s a schedule I’m not used to playing so my first goal was to start well, with a good rhythm. I think I did pretty well and after that just keep it going.”

Alcaraz is yet to drop a set and will next take on unseeded Frenchman Arthur Rinderknech, who ended the run of his countryman Benjamin Bonzi.

Bonzi followed up his first-round win over Daniil Medvedev, which hit the headlines after a spectacular meltdown from the Russian, with another five-set win but ran out of steam against Rinderknech.