Naomi Osaka thwarted Serena Williams' attempts to seal a record-equalling 24th Grand Slam singles title at US Open with a 6-2 6-4 victory in Saturday's final.
Williams imploded in a furious tirade against chair umpire Carlos Ramos, calling him a "thief", having already docked her a point, leading to a game penalty as she went down in shocking circumstances.
With light rain falling, tournament organisers announced the roof would be closed for the duration of the final, which favoured Williams who walked out onto Arthur Ashe Stadium to a thunderous ovation.
In the battle of youth against experience, Osaka was giving away 30 major finals and 16 years of experience, but she came out with a fearless attacking style of play as she showed no signs of nerves to earn the first break of serve after Williams double-faulted in the third game.
For 20-year-old Osaka, this was her first taste of a Grand Slam final but she stood up to powerhouse Williams, whose first-serve percentage dipped below 50, to break again two games later.
Although Williams stopped the run of games against her at five to hold for 5-2, it was Osaka who confidently served out the set in 34 minutes.
Williams stoked the fire after she was given a violation for illegal on-court coaching by Patrick Mouratoglou.
"I don't cheat to win. I'd rather lose," she told umpire Ramos, before channelled her anger towards the Indian Wells champion as she opened up a break-point opportunity in the fourth game, which Osaka saved following an outstanding 19-shot rally.
Osaka, who stunned her idol in the first round at the Miami Open earlier this year in straight sets, saved two more chances but was unable to withstand a third as an unforced error handed Williams a 3-1 lead.
She was, however, unable to capitalise with Osaka hitting back immediately while Williams anger bubbled to boiling point as she suffered an extraordinary meltdown by smashing her racket which handed her a second code violation, meaning a point penalty by which point the boos and jeers were deafening.
Osaka maintained her nerves and wrapped up a hold to love to level up at 3-3 in what was turning into a dramatic encounter.
"You owe me an apology," said Williams, who resumed the argument. "I have never cheated in my life!"
Osaka won her third game in a row by which time Williams lost her composure and a third outburst then earned her a game penalty, prompting a further verbal attack to tournament officials.
Williams held her next service game, but Osaka kept her cool to serve out the match and become the first Japanese player to win a Grand Slam singles title.