Williams Loses It At Umpire: 'You're A Thief' 'You Owe Me An Apology'

"You will never, ever, ever be on court of mine as long as you live:" The tennis great threatened umpire over cheating penalty.

Minutes after receiving a game penalty for verbal abuse against the chair umpire, Serena Williams lost the U.S. Open Women’s Final against Naomi Osaka on Saturday.

The 6-2 6-4 victory appeared routine enough but the one hour and 19 minute match will be long remembered for a row between Williams and the chair umpire.

The headlines were supposed to be about the American's bid for a record-equalling 24th grand slam title and Osaka trying to become Japan's first slam winner but instead an argument with umpire Carlos Ramos that escalated dominated the match.

Williams was furious when she was given a coaching violation early in the second set after a hand gesture from her coach Patrick Mouratoglou.

She was then docked a point for a second violation when she smashed her racquet after dropping serve at 3-3.

The 36-year-old Williams maintained that she "is not a cheater" and demanded an apology.

Continuing her argument with Ramos at the change of ends, Williams maintained that she "is not a cheater" and demanded an apology before she accused him of being a "thief" for taking a point away from her.

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Ramos gave her a third violation, which resulted in a game penalty, putting Osaka 5-3 ahead.

Williams continued arguing with tournament officials, fighting back tears, when they came onto the court to hear her pleas for fair treatment.

She insisted male players had called chair umpires much worse and she was being treated differently because she is a woman.

Despite the drama in her first major final, 20-year-old Osaka maintained her focus to serve out the victory.

Serena had words with the umpire. Image: Getty Images.

The presentation ceremony began with booing from the crowd before a tearful Williams said, to wild cheers: "I don't want to be rude. I don't want to do questions.

"I just want to tell you guys she played well. Let's make this the best moment we can and get through it and give credit where credit is due.

"No more booing. Let's be positive."

Osaka was also in tears, and said: "I know everyone was cheering for her and I'm sorry it had to end like this. I just want to say thank you for watching the match.

"It was always my dream to play Serena in the US Open finals. I'm really glad I was able to do that."

Serena Williams Outrage At Cheating Accusation