Umpire Carlos Ramos acted with "professionalism and integrity" in the controversial US Open final between Serena Williams and Naomi Osaka, according to the International Tennis Federation (ITF).

Ramos handed the former world number one a code violation for coaching after a gesture from Patrick Mouratoglou in the player's box, angering Williams, who asserted she does not "cheat".

COURT BLASTS SERENA FOR US OPEN OUTBURST

With the American trailing in the second set, she was issued a point penalty for smashing a racquet and responding by branding the official a "liar" and a "thief" resulted in her being docked a game.

Boos rang out inside Arthur Ashe Stadium following the decision, with a furious Williams calling for the match referee and alleging the situation would have been handled differently if she were a man.

The WTA backed Williams, who went on to lose 6-2 6-4 to Osaka, and questioned "different standards" in the women's and men's games, while the US Open fined her $17,000 for her three code violations.

Ramos' handling of the situation has drawn criticism in some quarters, but the ITF feels the 23-time major champion's sanctions from the US Open support his actions.

An ITF statement read: "Carlos Ramos is one of the most experienced and respected umpires in tennis. Mr Ramos' decisions were in accordance with the relevant rules and were re-affirmed by the US Open's decision to fine Serena Williams for three offences.

"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 and acted at all times with professionalism and integrity."

Williams was in tears as she finished the match and requested the crowd stop booing before Osaka was presented with the trophy for her maiden grand slam triumph.

The 20-year-old Japanese cried at the reaction from spectators and has since admitted to being "a little bit sad".