Naomi Osaka, who withdrew from the French Open on Monday after a bitter row over her refusal to appear at news conferences, has made a rapid and at times uncomfortable climb to the top.
The 23-year-old's zen-like mentality and increased gravitas on and off the court have elevated her alongside Serena Williams to being the one of the most recognisable female athletes on the planet.
An unceasing politeness away from the battlefield, coupled with the on-court steel that runs through all champions, makes her stand apart.
However, her decision to pull out of Roland Garros after just one match, having been fined $15,000 and threatened with expulsion for refusing to carry out media activity in Paris, has stunned the sport.
Osaka revealed her mental health struggles and constant feelings of self-doubt.
"The truth is I have suffered bouts of depression since the US Open in 2018 (her first Slam title) and I have had a really hard time coping with that."
She added: "In Paris, I was already feeling vulnerable and anxious so I thought it was better to exercise self-care and skip the press conferences."
During the height of the Covid-19 pandemic, Osaka became a vocal leader in the fight against racial injustice in the United States.
At the US Open in 2020, she appeared on court wearing face masks carrying the names of victims of individuals who had died of alleged police or racist violence in the United States.
Often painfully shy and uncomfortable in the spotlight, Osaka has used her growing stature to weigh in on controversial topics -- even condemning ex-Tokyo Olympics boss Yoshiro Mori for sexist comments during her Australian Open title run.
Osaka has also become the world's richest female athlete, overtaking Serena Williams. Last year, she earned $37.4 million.
But she had tried to maintain a humble and respectful attitude amid her rise to stardom.
Born on October 16, 1997 in, Osaka, Japan, a year later her family moved to the United States.
Her Haitian father Leonard met and married her mother Tamaki when he decamped to Japan from New York to study.
Now based in Florida, Osaka has dual Japanese-American citizenship.
Osaka developed into a big-stage player after making her Grand Slam debut at the 2016 Australian Open.
It took a few years to find her feet before she stunned Williams with a straight-sets victory in a controversial 2018 US Open final and backed that up with a triumph at Melbourne Park just a few months later.
- Demons reappear -
Osaka, at just 21, powered to world number one but she felt unfulfilled.
"I think that also put a lot of pressure on me because I just felt in a way it was me against the world," she said.
It led to a difficult period where she felt burdened by expectations until heeding a more relaxed demeanour.
"I used to weigh my entire existence on if I won or lost a tennis match," she said. "That's just not how I feel any more."
However, just three months later, the demons seem to have reappeared.
"The best thing for the tournament, the other players and my well-being is that I withdraw so that everyone can get back to focusing on the tennis going on in Paris," the world number two wrote on Twitter on Monday.
"I never wanted to be a distraction. The truth is I have suffered bouts of depression since the US Open in 2018 and I have had a really hard time coping with that."