Serena Williams thought she was treated more harshly by the chair umpire in the US Open final than a man would have been.

Williams was cited by official Carlos Ramos for three code violations during her 6-2, 6-4 loss to Naomi Osaka on Saturday (local time).

She first warned for receiving coaching signals, then deducted a point for breaking her racquet and finally lost a game for calling the chair umpire a “thief”.

“I’ve seen other men call other umpires several things. I’m here fighting for women’s rights and for women’s equality and for all kinds of stuff,” Williams said at her news conference.

“For me to say ‘thief,’ and for him to take a game, it made me feel like it was a sexist remark.

“He’s never taken a game from a man because they said ‘thief’. For me, it blows my mind. But I’m going to continue to fight for women.”

Earlier, as Williams pleaded her case on court with tournament referee Brian Earley, calling the penalties unfair, she said: “Because you’re a woman, you’re going to take this away from me?”

“There’s a lot of men out here that have said a lot of things and because they are men, that doesn’t happen,” Williams said.

Tennis greats back Williams’ claims

Two-time Australian Open champion and two-time US Open runner-up Victoria Azarenka backed up Williams’ stance, writing on Twitter: “If it was men’s match, this wouldn’t happen like this. It just wouldn’t”

Billie Jean King, who won 12 Grand Slam singles titles, helped found the women’s tennis tour and paved the way for equal prize money in the sport, said on Twitter that “several things went very wrong” during Saturday’s match.

“Coaching on every point should be allowed in tennis. It isn’t, and as a result, a player was penalized for the actions of her coach. This should not happen,” King wrote.

In a second tweet, King thanked Williams for calling out the “double standard” and said “more voices are needed to do the same”.

“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.”

Differing standards in tennis rules

There have been a series of recent happenings that illustrate the ways in which tennis does do things differently for men and women.

Just before the US Open, the French tennis federation president said that the black catsuit worn this year by Williams at the French Open would not be allowed at that tournament in the future.

During the US Open, a female player, Alize Cornet, was incorrectly admonished by a chair umpire for changing her shirt during a match, which is allowed and which men do all the time.

Last week the US Tennis Association created a new rule that allows for a 10-minute break in men’s matches when the heat and humidity are too harsh; previously, only women were given that chance for a delay.

“I just feel like the fact that I have to go through this is just an example for the next person that has emotions, and that want to express themselves, and want to be a strong woman. They’re going to be allowed to do that because of today,” Williams said.

“Maybe it didn’t work out for me, but it’s going to work out for the next person.”