Yuliya Putintseva was forced to issue a public apology after behaving “disgustingly” towards a ball girl during her third-round loss at the US Open.

Putintseva was booed at Louis Armstrong Stadium in New York after she snubbed a ball girl and refused to acknowledge her existence in an ugly moment that enraged tennis commentators.

Kazakhstan’s Putintseva apparently took out her frustration on the ball girl by staring at the back of the court while the ball girl was in position to pass her the balls for her next serve.

Viral videos show the 29-year-old rudely ignoring the young fan and not reacting when the ball girl threw her two balls.

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Curiously, Putintseva let the two balls bounce off her torso and leg before reluctantly picking up the third ball.

Putintseva then picked up one of the other balls and then went to the service line.

Her cool demeanor did not go unnoticed in the stadium and the crowd cheered her on for the rest of the game.

Fifth seed Jasmine Paolini was too good for Putintseva and the Italian moved into the fourth round with a 6-3, 6-4 win.

Tennis commentators around the world also cheered against Putintseva.

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German media star Boris Becker wrote on X, formerly Twitter: “What does Putintseva think she’s doing? Terrible behavior towards the ball girl.”

Australian champion Rennae Stubbs posted: “The disrespect and disgusting behaviour here is unbelievable and typical of her.”

Piers Morgan also shared a video of the incident and wrote: “Disgusting arrogance from @Putintseva. Yulia the ball girl should have thrown the third one in her mocking face.”

Leading American tennis commentator Jon Wertheim also wrote: “The boos were not nearly loud enough… that’s really pathetic.”

There was also a lot of praise for the way the ball girl handled the situation. The young tennis fan kept her cool and did her duty despite the anger that Putintseva was showing.

She was also seen shaking her head in disbelief as she returned to her seat at the back of the courtroom after the incident.

American tennis commentator Brad Gilbert wrote on Twitter: “A tremendous effort by the ball girl to raise her arms. Ball people should never be insulted as so many former players were also ball kids.” He also mockingly said Putintseva should have received a “straight red card”.

Putintseva finally responded to the outcry with a message on Instagram.

“I want to apologize to the ball girl for my behavior when she gave me balls,” Putintseva wrote in her Instagram stories.

“Honestly, it wasn’t about her. I was really mad at myself because I couldn’t win the match from the break point, and then I was so emotionally empty and lost in thought that I didn’t even focus on what was going on and who was giving me the ball.

“All the ball boys did great at the Open, as always.”

Paolini has now made it to the fourth round of all four Grand Slam tournaments this year, after never making it past the second round in 16 previous attempts.

She next plays against Karolina Muchova on Tuesday morning (AEST).