The US Open is under fire for sexism.
A female tennis player, Alizé Cornet, was hit with a code violation for changing her top on court.
Male athlete Novak Djokovic removed his shirt in a separate match and sat completely topless between games, but was left unpunished.
Andy Murray's mother Judy Murray, a tennis coach in her own right, claimed there are double standards at play.
The decision has been called "totally sexist."
The US Open has been accused of sexism after a male umpire punished a female tennis player for something men frequently do without fear of sanctions.
It all began during a Round of 128 match on Tuesday, when French player Alizé Cornet played Swedish star Johanna Larsson on Court 13 at Flushing Meadows.
A 10-minute heat break had been called as conditions reached sweltering point but, when play resumed, Cornet realised she was wearing her top the wrong way round.
Cornet then changed on the court, temporarily exposing her black sports bra — and was slapped with a code violation by the male umpire.
The decision to punish Cornet for changing on court was wildly rebuked on Twitter, with Judy Murray — mother of 2012 US Open winner Andy Murray — claiming there are double standards at play.
Murray said: "Cornet came back to court after 10 minute heat break. Had her fresh shirt on back to front. Changed at back of court. Got a code violation. Unsportsmanlike conduct. But the men change shirts on court."
Alize Cornet came back to court after 10 minute heat break. Had her fresh shirt on back to front. Changed at back of court. Got a code violation. Unsportsmanlike conduct..... 😳
But the men can change shirts on court. https://t.co/sCN4KDXYTb
— judy murray (@JudyMurray) August 28, 2018
Indeed, Novak Djokovic went unpunished when he removed his shirt completely on the same day Cornet received her warning.
During Djokovic's match with Marton Fucsovics, which he won three sets to one, the players — like Cornet and Larsson — were permitted a 10-minute respite from the heat.
Djokovic struggled in the soaring temperatures, removed his shirt, and toweled himself down at one point during the game.
(Photo via AFP/Getty Images)
Cornet's treatment is a stark contrast to Djokovic's, and Fox 35 Good Day Anchor Bob Frier believes this is "totally sexist."
In a tweet published on Wednesday, Frier said: "Totally sexist! US Open umpire hits French player with a code violation after she quickly turns her shirt around because it was on backward. Male players do it… and she was covered the whole time. Sorry, but that's wrong."
WTA rules state women are not allowed to change while on the court, according to the Daily Mail. But there is no rule for men.
Totally sexist! US Open umpire hits french player with a code violation after she quickly turns her shirt around because it was on backward. Male players do it.. and she was covered the whole time. Sorry but that's just wrong. #fox35https://t.co/aVpAjhrRwj
— Bob Frier (@FrierBob) August 29, 2018
This is not the first time a major tennis tournament has attracted headlines for the way it treats its female athletes.
Just last week, 23-time Grand Slam champion Serena Williams was told by the French Open president that she would never be allowed to wear her "Black Panther"-style catsuit at the tournament again.
Bernard Giudicelli implied her outfit did not show respect for the game or the competition.
Cornet lost her Round of 128 match by two sets to one, but will remain at the US Open as she is scheduled to compete in a doubles match with Romanian partner Irina Bara.
They take on Russian player Vera Zvonareva and Swiss star Timea Bacsinszky on Court 14 at 13.35 local time.