Former world number one Naomi Osaka told the capacity crowd in Indian Wells, California that she was brought to tears during her defeat against Veronika Kudermetova because a heckle from the crowd reminded her of similar disrespectful treatment handed out to Venus and Serena Williams at the same event several years ago.
Osaka, who has created several headlines throughout her recent career due to a perceived inability to handle criticism, broke down during the first set when, after having her serve broken in the first game of the match, a fan shouted, "Naomi, you suck!"
The Japanese star – winner of four Grand Slam titles during her career – was visibly shaken by the criticism and asked the chair umpire if the offending fan could be ejected from the arena.
She also asked to use the umpire's microphone to address the audience in between games. Both requests were rejected by the umpire.
The crowd interjection appeared to stifle Osaka as she lost the match 6-0, 6-4.
Afterwards, though, Osaka was granted the opportunity to speak to the crowd – something of a rarity for a losing player.
"To be honest, I've gotten heckled before, it didn't really bother me," she said, again struggling to hold back tears.
"But [being] heckled here, I watched a video of Venus and Serena [Williams] getting heckled here, and if you've never watched it, you should watch it. I don't know why, but it went into my head, and it got replayed a lot. I'm trying not to cry."
Osaka was referencing an incident which at the event 21 years ago, when Venus Williams and her father, Richard, were jeered by the crowd as they watched Serena play in the final match against Kim Clijsters.
Both boycotted the event for more than a decade afterwards – with Serena later admitting that the incident still affects her.
"Even when I went back 14 years later, it was very traumatizing," Serena told Red Table Talk last year. "Talk about post-traumatic stress and mental anxiety.
"I remember sitting in the bathroom thinking, 'Wait, I'm not gonna go back. I just don't think I should do this. What if they start booing again?' It was really hard for me."
Osaka has noted her struggles with mental health on several occasions since her most recent major win at last year's Australian Open.
She later withdrew from the French Open, didn't compete at Wimbledon and then announced she was taking a hiatus from the sport after her elimination from the US Open in September.
The 24-year-old returned as the 13th seed at the Australian Open in January but was beaten in the third round by current world number 43 Amanda Anisimova.
Her world ranking has dropped to 78 just over two years after she was ranked as the world's top female player.
Kudermetova will take on Marie Bouzkova in her third-round match after defeating Osaka.