Former world number one Naomi Osaka was brought to tears by a heckler during her 6-0 6-4 defeat by Veronika Kudermetova at Indian Wells.
The four-time Grand Slam winner was taunted in the first set by someone in the crowd yelling “Naomi, you suck”.
Osaka was playing her third event since taking a break in September.
Speaking on court after the match, an emotional Osaka said it reminded her of Venus and Serena Williams being heckled at the same tournament in 2001.
While holding back tears, Japan’s Osaka said: “I’ve been heckled before and it didn’t really bother me.
“But being heckled here. I’ve watched video of Venus and Serena get heckled here and if you’ve never watched it, you should watch it. And I don’t know why, but it went into my head and got replayed a lot.”
The Williams sisters boycotted Indian Wells for 14 years over the events of 2001.
Venus had pulled out of a semi-final match against her sister with a knee injury, and when she and her father Richard took their seats to watch Serena in the final against Kim Clijsters the next day the crowd jeered. Serena was also subjected to boos throughout the match.
Serena went on to win the title and embraced Venus and her father courtside, with Richard later saying he was the target of racial abuse.
In an interview in 2021, Serena said she was still traumatised by the incident two decades later.