Naomi Osaka wins after Serena Williams outburst

The American was furious, walking up to Ramos, shouting and pointing at him as the crowd started booing in support of the former world number one.

The drama continued as the atmosphere in Ashe became more toxic.

Williams, still angry with Ramos for the previous two violations, refused to let the issue slide and launched an extraordinary rant at him at the changeover with Osaka leading 4-3.

"You are a liar. You will never be on a court of mine as long as you live. When are you going to give me my apology? Say you are sorry," she told him.

That led to Ramos docking her the next game - leaving Osaka just one more away from victory at 5-3 up.

Boos continued to rain down, generating incredible noise, as Williams refused to take to the court and demanded an intervention from the tournament referee.

Eventually she returned to the baseline, serving out a game to love before Osaka showed remarkable focus to hold the final game for her first Grand Slam win.

Williams later accused the umpire of sexism, saying: "He's never taken a game from a man because they said 'thief',"

Boos, anger & tears

Williams is a national icon in the United States, as well as a global star around the world, and had the backing of the 24,000-capacity Arthur Ashe Stadium.

But the boisterous crowd was quietened as Osaka came out firing at the six-time champion.

Osaka, playing in her first Grand Slam final and against her idol, showed no fear as her aggressive approach led to multiple errors from Williams' racquet.

Williams' first serve percentage was down at 38% and made 13 unforced errors as Osaka broke for 2-1 and 4-1 leads on her way to the opening set.

The Ashe crowd, whilst remaining respectful towards Osaka, was already upset with the way Williams had been treated by Ramos and unhappiness turned to anger during the madness of the second set.

Security staff ran on to the perimeter of the court as Ramos walked off and the Portuguese did not return, as he would usually have done, for the trophy presentation.

More boos followed at the start of the ceremony, leading to Osaka pulling her visor down over her eyes to hide her tears.

Williams appealed for calm in her runners-up speech, asking her supporters to "give credit" to Osaka's achievement.

The Japanese player composed herself as the crowd began to applaud her, although she almost dropped the trophy as she walked off the stage.

"It was always my dream to play Serena in the US Open finals so I am really glad I was able to do that," she said.

Third time angry for Serena

"This has happened to me before, this is not fair," Williams told the umpire after she was docked the point for racquet-smashing, apparently referring to two previous controversies at US Open matches.

The American received a point penalty on match point of her 2009 semi-final against Clijsters following a tirade at a line judge.

The Belgian was two points from victory when Williams, who had earlier been given a code violation for racquet abuse, was called for a foot-fault.

Williams launched an angry outburst at the official and got the point penalty, meaning Clijsters won 6-4 7-5.

She later apologised.

That incident in the match against Clijsters left Williams on a two-year probation period, leading to a $2,000 (£1,265) fine after she abused umpire Eva Asderaki in the 2011 final where she lost to Sam Stosur.

"If you ever see me down the hallway look the other way," she told Asderaki. "You're out of control. You're a hater and you're just unattractive inside."