Jannik Sinner was determined he would not become the third big-name casualty at the US Open in three days.

World number one Sinner’s route to winning a first title at Flushing Meadows – and second grand slam of his career – became a lot easier since he last played after favourites Carlos Alcaraz and Novak Djokovic both crashed out.

Sinner was in no mood to join them on an early flight home as he breezed past Australian Christopher O’Connell in straight sets.

“It shows that this sport is unpredictable,” the Italian said.

“Whenever you drop a little bit of your level, if it’s mental, if it’s tennis-wise or physical, at the end it has a huge impact on the result.

“Both opponents who they lost against, they played some incredible tennis. And it happens.

“So I just watch on my side what I have to do that I guess I have done also in the last period of time, and then we will see what I can do. That’s it.”

Sinner will be pleased Alcaraz and Djokovic’s shock exits took the attention away from him and the controversy surrounding his two failed anti-doping tests earlier this year.

Jack Draper said his win over Alcaraz’s slayer Botic van De Zandschulp was not a gimme as he booked his place in the fourth round.

The 22-year-old, who has equalled his best run at a grand slam, won in straight sets on Grandstand court.

But Draper said he had work to do, even if it was a predictable case of after the Lord Mayor’s Show for the Dutchman.

“I think it is sometimes difficult when people are saying, ‘Oh, like, he should definitely win this match’,” he said. “Botic’s just beaten the number two in the world who’s won multiple grand slams this year.

“He obviously played a really good match and can definitely beat me too.”

Draper will next play Tomas Machac, who beat David Goffin.