Tennis legend blames prawn tacos as Coco Gauff vomits, several withdraw sick from Madrid Open

A mystery illness has floored some of the world's top tennis players at the Madrid Open, forcing several to quit the tournament and American star Coco Gauff to vomit during a match.

American legend turned respected commentator Jim Courier suggested the issue stemmed from bad prawn tacos being served to players somewhere around the facility, after several claimed to have contracted food poisoning.

Others said it was some kind of virus which was causing the illness.

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Gauff advanced to the fourth round of the Madrid Open despite falling ill and vomiting into a bin courtside during her clash with Sorana Cirstea.

Gauff, a finalist in Madrid last year, rallied to beat Cirstea 4-6, 7-5, 6-1 after the American threw up in the middle of the second set, and had to have her blood pressure taken by medical staff.

“When I actually threw up on the court, that was like a little bit embarrassing," Gauff said.

“Then after that first game and the second, I was like that took everything out of me."

On Saturday, fourth-ranked Iga Swiatek withdrew due to an unspecified illness while playing her round-of-32 match against American Ann Li.

Madison Keys withdrew from the tournament before it began, citing illness, while fellow players Liudmila Samsonova, Marin Čilić, and Corentin Moutet are others to have fallen ill.

"The last two days were pretty terrible. I think I have some virus," Keys said.

"There's something going on between the players; the virus is somewhere on site."

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Cilic believed he contracted food poisoning, but did not say where he thought it came from.

"Unfortunately, I got food poisoning yesterday," he wrote on Instagram.

"After trying to recover all night, my body is unfortunately exhausted and not at the proper level to get into the battle. Apologies to all the fans who were waiting to watch the match."

Moutet lost in straight sets to local hope Daniel Merida Aguila and then revealed he had been "fighting with a virus" for several days.

Gauff said she was determined to carry on her match.

“I’m someone who doesn’t like to pull out. I don’t like to do that unless I really feel like I have no other options,” Gauff said.

"So the plan was to always just try to finish, even if it ended up with me just playing just to get through it.”

She recovered from a break down three times before winning the set 7-5.

The third-ranked Gauff said she doesn't know how she “got through that", and said she almost threw up in the middle of a point.

“I felt fine all this morning. I felt a little weird last night, but I was OK. Woke up this morning, felt fine. And mid-first set, I was feeling like I was going to throw up. And then I did," she said.

"They gave me some pills and that definitely helped. After that, once I felt the feeling of throwing up, then I just felt nauseous and tired. I just didn’t want to throw up in the middle of the point, which I almost did at one point.”

Gauff will next meet No.13 seed Linda Noskova.