Serena Williams’ behaviour in Saturday’s US Open final divided the tennis world after she called the chair umpire a “liar” and a “thief” and said he treated her differently than male players during her loss to Naomi Osaka.

Seeking a record-equalling 24th grand slam singles title, Williams was handed a warning for a coaching violation before being deducted a point for smashing her racquet.

She then had a heated argument with chair umpire Carlos Ramos, which cost her a game.

The six-times Open champion, who has since been fined $US17,000 by the USTA for the violations, vigorously disputed each during the match.

In the wake of Osaka’s first grand slam triumph, there were messages of support for Williams as well as those condemning her behaviour and agreeing with the umpire’s calls.

Tennis great Billy Jean King wrote on Twitter: “When a woman is emotional, she’s “hysterical” and she’s penalized for it. When a man does the same, he’s “outspoken” and there are no repercussions. Thank you, @serenawilliams, for calling out this double standard. More voices are needed to do the same.”

Yet Australian Margaret Court, whose tally of grand slam singles titles is being chased by Williams, had little sympathy for the 36-year-old American former world No.1.

“We always had to go by the rules,” Court, who dominated tennis during the 1960s and early 1970s, said according to a report in The Australian.

“It’s sad for the sport when a player tries to become bigger than the rules.”

The drama started when Ramos handed Williams a coaching violation early in the second set because of hand gestures made from the stands by her coach Patrick Mouratoglou. He later admitted the offence, which that is not allowed in the sport but rarely enforced.

When the violation was announced Williams approached Ramos to insist she never takes coaching and would rather lose than “cheat to win”.

Tennis great John McEnroe, one of the game’s most tempestuous characters in his playing days, said the sport must find a way to allow players to express feelings and inject their personality into the game while adhering to certain rules.

According to McEnroe, Ramos should not have given Williams a violation for breaking her racquet and should have warned her early on about what would happen if she did not move on.

“I’ve said far worse,” McEnroe, a seven-times Grand Slam singles winner, said on ESPN. “She’s right about the guys being held to a different standard, there’s no question.”

Yet Richard Ings, a former professional chair umpire who also used to be the ATP Tour Executive Vice-President, Rules and Competition, felt it was Williams who needed to apologise.