Last updated on .From the section Tennis

The US Open final umpire whom Serena Williams called "a thief" has been defended by tennis' governing body.

Williams, beaten in straight sets by Naomi Osaka, was docked a game for verbal abuse, having already had a point penalty for smashing her racquet and a code violation for coaching.

She later said it was "sexist" to have been penalised a game.

The International Tennis Federation said Carlos Ramos acted "at all times with professionalism and integrity".

An ITF statement said: "It is understandable that this high-profile and regrettable incident should provoke debate. At the same time, it is important to remember that Mr Ramos undertook his duties as an official according to the relevant rule book.

"Mr Ramos' decisions were in accordance with the relevant rules and were reaffirmed by the US Open's decision to fine Ms Williams for the three offences."

However, Williams' claims have been backed by the governing body of women's tennis, the WTA.

Chief executive Steve Simon said: "The WTA believes that there should be no difference in the standards of tolerance provided to the emotions expressed by men versus women.

"We do not believe that this was done."

Osaka, 20, won Saturday's match 6-2 6-4 to become the first Japanese Grand Slam champion.

Williams, who was aiming to equal Margaret Court's record of 24 Grand Slam singles titles, refused to shake hands with umpire Ramos after the match.

Her $17,000 (£13,100) fine for the code violations, imposed by the United States Tennis Association, will be deducted from the $1.85m (£1.42m) she won as the runner-up.

What happened in the match?

The issues began when Williams' coach Patrick Mouratoglou made a hand gesture towards her early in the second set at New York's Flushing Meadows - the rules say "communication of any kind" between player and coach is banned in Grand Slams.

Williams denied she received coaching, saying she would "never cheat to win and would rather lose", and demanded an apology from the umpire Ramos.

Mouratoglou, however, later admitted coaching - although he said Williams was not looking at him.

Three games later Osaka was awarded a point when Williams was given another code violation for smashing her racquet.

Williams was furious, walking up to Ramos, shouting and pointing at him as the crowd started booing in support of the American in a toxic atmosphere.

At the next change of ends, Williams continued to rant, calling Ramos a "liar", telling him to "say you are sorry" and describing him as a "thief" for awarding a point to Osaka.

"For me, it blows my mind," the 23-time Grand Slam champion said. "But I'm going to continue to fight for women and to fight for us to have equality.

"This is just an example for the next person that has emotions, that wants to express themselves and wants to be a strong woman.

"They're going to be allowed to do that because of today. Maybe it didn't work out for me, but it's going to work out for the next person."