Alcaraz makes no excuses after shock second-round exit at US Open

Unseeded Van de Zandschulp was a huge underdog against a player who had won 15 straight Grand Slam matches and fans inside Arthur Ashe Stadium could scarcely believe their eyes as Alcaraz dished out error after error in the shock loss.

"I think my level stayed at the same point all the match, and it wasn't enough to win the match or to give myself the chance to getting into the match or trying to give myself chances," he said.

"So, you know, what can I say? I didn't feel well hitting the ball. I think I made a lot of mistakes. When I wanted to come back or I think I wanted to come back, it was too late."

Alcaraz, winner of the last two Grand Slams at Roland Garros and Wimbledon, had made it to at least the quarter-final stage at every major in which he has competed since winning the US Open two years ago.

But there were warning signs for him, who won silver at the Paris Olympics, was not firing on all cylinders in the run-up to Flushing Meadows, losing to Gael Monfils in the second round of the Cincinnati tune-up tournament.

"I came here with not as much energy as I thought that I was going to come. But, I mean, I don't want to put that as excuse," he told reporters.

"Probably I'm a guy or I'm a player that needs more days or more break coming into the good tournaments or the important ones. So I have to think about it, and I have to learn about it."

Van de Zandschulp will next face Britain's Jack Draper.