NAOMI Osaka has made history beating Serena Williams to claim Japan’s first ever Grand Slam title, but it was Williams’ rolling feud with the umpire that threatens to steal the spotlight.

Williams’ bid for a 24th Grand Slam title imploded in a furious tirade against umpire Carlos Ramos, calling him a thief after he docked her a point for two code violations.

“I don’t cheat to win, I’d rather lose,” Williams told Ramos after being handed the intiial code violation for receiving coaching advice from her box.

“I didn’t get coaching. You owe me an apology. I have never cheated in my life.”

Her outburst then earned her a game penalty, prompting a further outburst to tournament officials and putting Naomi Osaka within one game of victory.

“Are you kidding me? You will never, ever, ever be on another court of mine as long as you live,” Williams roared at Ramos.

“You are the liar. When are you going to give me my apology? You owe me an apology. Say it. Say you’re sorry. ... And you stole a point from me. You’re a thief, too!”

Williams then demanded that tournament referee Brian Earley be brought to the court, where her incredible rant continued.

“This is not fair. This has happened to me too many times,” she told Earley.

“There’s a lot of men who do a lot worse out here. It’s because I’m a woman.”

Later, there were some raw and honest admissions from Serena’s coach Patrick Mouratoglou, who admits he was coaching her during the match - but says it is something which all coaches do in every match.

“Well, I mean, I’m honest: I was coaching. I don’t think she looked at me so that’s why she didn’t think I was (coaching),” Mouratoglou told ESPN.

“But I was (coaching) like 100 per cent of the coaches in 100 per cent of the matches. So we have to stop this hypocrisy. (Osaka’s coach) Sasha (Bajin) was coaching every point too.”

Mouratoglou touched on one of Williams’ complaints - that similar things happen in the men’s game, that go unpunished.

“It’s strange because this chair umpire was the chair umpire of most of the finals for Rafa (Nadal) and (his coach) Toni is coaching every single point, and he never gave a warning. So I don’t really get it,” he said.

When asked if Serena understand rule that coaching violation went against her, and the subsequent racquet break equals a point against her, Mouratoglou replied: “I don’t think so. But she’s in her match, she shouldn’t have to think about that. She should be able to express her emotions. There are positive emotions, negative emotions. She’s human. Those rules are killing tennis. I’ve always said this: not to allow the players to express their feelings is stupid. It’s not a big deal breaking a racquet, I think.”

And has he ever been handed a code violation before? “Not once in my life. You can check the records, you’ll see. It’s strange to happen in a grand slam final.”