"I feel like even though I should enjoy this moment, I should still think of it as another match", she said. "And I don't understand why he didn't do that, where all the other chair umpires do this all year long, including him'".
In the 2011 US Open final, chair umpire Eva Asderaki warned Williams for hindering opponent Stosur for shouting "come on" before the Australian had reached the ball.
Her on-court message to Williams was simply: "I love you", but Osaka insists she will not be happy simply to share the same stage on Saturday.
And even though Williams may have lost the match, she also got a piece of it: As the women's singles runner-up, Williams received $1.85 million.
She resumed that argument after the second violation, still angry about the first violation.
Losing that momentary lead in a game where she double-faulted twice was too much for Williams to handle and she took it out on her racket, which she smashed into the ground. She briefly disputed that ruling, saying cheating "is the one thing Ive never done, ever". "I have never cheated in my life!"
Both are powerful, aggressive players with strong serves and the influence of Williams' style on Osaka's game is clear.
Then her frustration boiled over. Her spiraling anger at the call, most of it seemingly at the notion that she would cheat, caused her to lose focus.
Sneak peek into Priyanka & Nick’s famjam at US Open
Nick's parents Paul and Denise and Priyanka and her mother Madhu Chopra accompanied the soon-to-be-married couple to St. Priyanka and Nick confirmed their engagement on August 18 in Mumbai with a traditional roka ceremony.
"I know that everyone was cheering for her", Osaka told the crowd, "and Im sorry it had to end like this".
One of the two will make history on Arthur Ashe Stadium court, where Williams won the first of her six US Open titles at the age of 17.
But Osaka, who displayed not only a stellar game but remarkable poise throughout, held serve to seal a historic win for her country.
Osaka was only a year old when Williams won her first slam title here in 1999. That was the third violation, which took a game away.
Naomi Osaka's first grand slam title resulted in her being emotional and crying when handed the trophy.
And the two had an encounter four years before when Osaka was a 16-year-old fan meeting her favorite player.
Naomi Osaka walked to the net, the excitement of being a Grand Slam champion mixed with a bit of sadness.
She will turn 37 on September 26, unsure when she'll fully get back to the player she was before her health scares. Osaka, 20, would become the youngest U.S. Open champion since Maria Sharapova was 19 in 2006. During the U.S. 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.
Tournament officials have yet to comment.