Spanish tennis star Carlos Alcaraz crashed out of the US Open after appearing to vomit into his towel during a dramatic five-set quarterfinal defeat to Ben Shelton (USA).

The defending champion appeared to struggle physically during the match on Wednesday, with cameras showing him turning away from the court and appearing to vomit into his towel during the changeover after the fourth set.

Despite the difficult moment, Alcaraz continued and fought back from losing the second and third sets to force a deciding fifth.

Shelton eventually completed a stunning upset, defeating the 23-year-old Spaniard 6-7(5), 6-1, 6-3, 1-6, 7-6(7).

Turning from cameras

The moment Alcaraz appeared to be sick immediately caught the attention of fans watching around the world.

Former American tennis player James Blake said Alcaraz did not want the camera to show him being sick and asked the cameraman to look away.

Shelton dominated the second set and won it 6-1 before taking the third set 6-3 to move within one set of a huge upset.

Alcaraz refused to give up. The defending champion raised his level in the fourth set, racing through it 6-1 to force a deciding fifth.

Resilient player

Fans have praised Alcaraz for continuing despite his physical struggles.

Speaking to reporters after the match, Alcaraz said he was “happy” and “proud.”

“Well, as I said before the tournament began, my expectation was to go there, compete, play in these kinds of matches, for me, being healthy,” said the 23-year-old Spaniard.

“So, it was close. It was close. So, I’m just a little bit disappointed about not getting the win, but I’m just happy. I’m just proud of myself, about how I fought.

“After the third set, physically I was really tired, but I found a way to push myself up and physically give extra. In the fifth set, I just started to feel better and better. Shelton is an unbelievable and powerful player, so credit to him.