'Zombie' Ons Jabeur refuses to let illness defeat her as she continues US Open run

Ons Jabeur said an illness has left her feeling like a "zombie" but the fifth seed showed will determination to battle past Czech teenager Linda Noskova 7-6, 4-6, 6-3 to reach the US Open third round.

Tunisian Jabeur suffered breathing difficulties during her gritty first-round win over Colombia's Camila Osorio and was not at her best against Noskova, getting through a tough match in a little over two hours.

Jabeur, 29, said she had been struggling for about a week with the illness and was "taking a lot of medicine".

"I'm a zombie because I have a flu," said Jabeur. "I'm doing everything I can with my team trying to recover," she added. "They have amazing doctors here, so they've been helping me. I basically took every medication they have.

"I'm glad it was two matches, two tests. I was trying to push myself to see what I can do, getting out of the comfort zone. Hopefully I'll continue in better shape and feel better for the next match."

Jabeur faces another Czech in Marie Bouzkova and is determined to continue her run.

"Emotionally I could be tired, but I know if I just let go I'll regret it after, so I want to continue and stay in New York as long as I can," she said.

Several players at the year's final Grand Slam have been hit by illnesses, including Dominic Thiem, Chris Eubanks and Hubert Hurkacz.

Carlos Alcaraz of Spain returns a shot against Lloyd Harris of South Africa. AFP

Carlos Alcaraz and Daniil Medvedev moved quietly into the third round while big-hitting American John Isner delivered his trademark stack of aces in taking his final bow at Flushing Meadows.

Alcaraz entertained a record crowd at Arthur Ashe Stadium with a 6-3, 6-1, 7-6 win over Lloyd Harris but the match also revealed a lack of sharpness