It was her maiden Grand Slam title, she had beaten the great Serena Williams to win it, and she had a bright future ahead.
Except that the victory had come in unusual and traumatic fashion, with boos and controversy surrounding Williams’ infamous outburst at the umpire.
And we now know that this title also marked the start of the “long bouts of depression” that have led to Osaka pulling out of the French Open in a move that has sent shockwaves through the sport and raised the prospect of some soul-searching for the authorities and media.
Roland Garros is now without one of the sport’s biggest stars, and despite Osaka’s desire to not “be a distraction” she and the issues she raises are firmly in the spotlight.
Did the authorities handle things well?
Osaka received a lot of support from fellow players and athletes over her decision to boycott news conferences at Roland Garros.
And there was criticism of the sport’s governing bodies’ strongly-worded statement on Sunday, which threatened her with expulsion from the French Open and future Grand Slams over what she said was a decision based on wanting to protect her mental health.
American basketball player Stephen Curry was critical, saying the “powers that be don’t protect their own”, while former British number one Laura Robson also questioned whether the matter could have been dealt with differently.
“I’m sure a lot of people are disappointed with how the statement was handled yesterday from the Grand Slams and how strong it was,” Robson said on BBC Radio 5 Live.
“Maybe if they had not let it escalate to this point then we wouldn’t be here.”
In a statement after Osaka’s withdrawal French Tennis Federation president Gilles Moretton said major tennis bodies were committed to athletes’ wellbeing and improving their tournament experience, including their interaction with the media.
Osaka said “the rules are quite outdated in parts” and she wants to discuss with the Tour ways of making things better.