The player at the centre of a tennis sportsmanship storm has doubled down, refusing to apologise for an act that left her opponent in tears and tennis world outraged.

Chinese player Zhang Shuai broke down in tears and retired from the match at the WTA Hungarian Grand Prix in Budapest on Wednesday with commentators suggesting she had suffered a panic attack as a result of an incident in the first set.

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Shuai was robbed of a point during her match against local player Amarissa Toth — and the situation quickly exploded into a moment of immense controversy.

The 20-year-old Hungarian was eventually handed the victory after Shuai’s retirement at 6-5 in the first set.

The situation exploded when Shuai sent a groundstroke crosscourt to Toth’s right hand side. The ball appeared to land right on the line where the sideline meets the corner of the service box.

Shuai was stunned to see the ball was called out and argued with the chair umpire for several minutes. She eventually called for a tournament supervisor to be brought to the court to address the matter.

Play had continued for one more point after the controversy at 15-15, but the disagreement over the call continued.

After calling for the tournament official to resolve the matter, Shuai spotted Toth walking to the area of the court where the ball landed and told her opponent not to cross out the mark with her shoes.

Toth, however, was seen on the TV cameras wiping the mark away with her shoes before the officials could have another look at it.

Shuai was heard yelling from the other side of the court: “Wait, wait, wait, keep the mark. What are you doing? Why would you do that?”

Toth appeared to respond by saying: “Because you’re making problems, that’s why.”

Shuai was seen looking absolutely devastated at the change of ends following the service game and a tournament doctor was eventually called onto the court.

Commentators noted that Shuai was shedding a “flood of tears” after the incident.

Shuai was eventually able to get back to her feet and offered brief handshakes with the chair umpire and Toth before quickly walking off the court while pointing at sections of the arena.

Toth held her hands in the air and celebrated immediately after the hand shake.

But the young Hungarian hasn’t apologised since, in fact accusing Zhang of making “a fuss”.

“I didn’t understand why she made such a fuss about it, that she wanted to overrule the umpire’s decision,” Toth said, per M4Sport.

“I don’t understand why she didn’t accept it, all in all, it was she who was looking for trouble.”

A day after the incident, the WTA said in a statement: “The WTA has zero tolerance for racism in any form or context.

“The unfortunate incident that took place today at the Hungarian Grand Prix and subsequent posts are being reviewed and will be addressed.”

The statement appears to refer to a comment made by the Hungarian GP’s official account on Facebook.

The comment read: “Amarissa did not decide if the ball was good or not. It was the decision of the linesman and then the chair umpire.

“The Hungarian tennis player in the first WTA match of her life may not have behaved in every situation, but she did nothing that could be described as a lack of integrity.

“And there is no deflection, no misunderstanding. The Chinese are manipulating the world with a manipulative video.”

The reference to “the Chinese are manipulating” prompted calls for the Hungarian Grand Prix’s tournament licence to be revoked.

Shuai addressed the matter on social media after the match on Wednesday morning.

“All efforts on practice was wrong, because when you wanted hitting closer to the line, even touched the line still OUT,” Zhang wrote later.

“I love you guys and all girls who supporting me and standing (by) my side.”

Toth has faced an avalanche of condemnation as a result of her conduct.

Countless players rallied around Zhang and condemned Toth for the blatant unsportsmanlike act.

Australian doubles star Ellen Perez was among the first to declare her disappointment.

“Well that’s a quick way to lose respect from your peers. I’m actually shook by the level of disrespect from this girl,” Perez wrote.

“If I see this girl tomorrow I will tell her how disgusted I am.”

Ajla Tomljanovic posted on Twitter: “Absolutely disgusting behaviour. Shuai is a better person than a lot of us for shaking the ref and that girl’s hand. But then again it’s Shuai we are talking about, of course she did”.

Aussie Daria Saville wrote: “Zero respect for this Toth girl. ZERO! I am so so so mad. I feel so bad for Shuai. Toth ‘won’ this point and ‘won’ this match but her reputation is ruined.”

Toth, meanwhile, next faces Ukrainian Kateryna Baindl in the Round of 16 on Thursday night.