Last updated on .From the section Tennis

Alize Cornet took her top off briefly after putting it on back-to-front

2018 US Open Venue: Flushing Meadows, New York Dates: 27 August-9 September Coverage: Live radio coverage on BBC Radio 5 live sports extra; live text commentaries on the BBC Sport website

The WTA has criticised US Open rules which saw French world number 31 Alize Cornet given a code violation for taking her shirt off on court.

Cornet changed her shirt during the break between the second and third sets during her first-round defeat by Johanna Larsson, but realised it was back-to-front and switched it on court.

But the chair umpire gave her a warning - a decision the WTA called "unfair".

US Open organisers said they "regret" that Cornet was given a code violation.

A WTA statement said the umpire's ruling "was not based on a WTA rule, as the WTA has no rule against a change of attire on court" and added that "Alize did nothing wrong".

Cornet, 28, lost 6-4 3-6 2-6 to Sweden's Larsson in the searing New York heat.

In a statement, the United States Tennis Association (USTA), which organises the US Open said: "All players can change their shirts when sitting in the player chair. This is not considered a code violation.

"We have clarified the policy to ensure this will not happen moving forward. Fortunately, she was only assessed a warning with no further penalty or fine.

"Female players, if they choose, may also change their shirts in a more private location close to the court, when available. They will not be assessed a bathroom break in this circumstance."

On Tuesday, temperatures close to 38C (100F) at Flushing Meadows were made more stifling by humidity levels of more than 50%, with five male players forced to retire because of heat-related issues.

Former Australian tennis player Casey Dellacqua called Cornet's warning "ridiculous" while five-time Grand Slam doubles champion Bethanie Mattek-Sands said it was "weak".