Novak Djokovic quickly recovering from a lower back problem to end British singles interest at the US Open as he blasted his way past Cameron Norrie 6-4 6-7 (4-7) 6-2 6-3 to reach the fourth round.

Norrie followed Emma Raducanu in exiting the tournament before the middle weekend, with the 30-year-old losing to the 24-time Grand Slam champion Djokovic on his Arthur Ashe Stadium debut.

Djokovic, who has now beaten Norrie in all seven of their meetings, said of his physical condition: “It’s all right. You don’t want to reveal too much to the rivals watching this.

“I’m good, as young as ever, as strong as ever. It’s New York, even if you’re feeling something body-wise, the energy just overrides it.”

Djokovic took a medical timeout during the first set after appearing to hurt his back, wincing and trying to stretch it out.

The 38-year-old was already a break ahead and he served out the opening set after the match resumed, while he then had more treatment early in the second.

The British No 2 , who was bidding for his first win against a top-10 player at a Grand Slam, fought back from 0-40 at 3-3 and kept the pressure on Djokovic, who was making increasingly agitated gestures towards his box.

Djokovic gained an early lead in the tie-break but Norrie took advantage of a slice of fortune thanks to the net cord to pull back to 3-3 and extended his run of points to five in a row with his best passage of play of the match.

His opponent saved one set point but then double-faulted and, when Norrie broke serve in the opening game of the third set, a shock looked possible.

He could not cement the break, though, and with a double fault the momentum switched again as Djokovic went on a run of four games in a row.

Still there were signs that all was not entirely well, with the Serbian barely appearing to try in Norrie’s service game at 4-1 before locking in again to take first the set and then the match as he veered from looking in real bother to playing his best tennis of the tournament.

“Overall, it was probably the best serving performance of the tournament,” Djokovic said. “Of course, I’m glad for that. It’s probably one of the most, if not, the most important shot in the game. So I’m glad how I executed that shot.”

German Jan-Lennard Struff knocked out American 17th seed Frances Tiafoe 6-4 6-3 7-6 (9-7), clinching the match with a hard-fought tie-break victory in the third set to reach the fourth round.

American sixth seed Ben Shelton retired injured against unseeded Frenchman Adrian Mannarino with the pair locked at two sets all.

Mannarino came back from a set down to level at 3-6 6-3 4-6 6-4 when Shelton shook hands with his opponent.

The Frenchman will face Czech Jiri Lehecka in the fourth round.

Alcaraz yet to drop a set in another dominant display

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

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.

Watch the US Open in New York, live on Sky Sports or stream with NOW and the Sky Sports app, giving Sky Sports customers access to over 50 per cent more live sport this year at no extra cost. Find out more here.