Serena Williams made herself ill after eating dog food hours before reaching the last eight of the Italian Open.
The world number one tried "a spoonful" of food meant for her dog, Chip, before beating fellow American Christina McHale in straight sets in Rome.
"I thought 'what the heck, I'm gonna try a piece, it looks good'," she said.
"Fast forward two hours, I just ran to the toilet like I thought I was going to pass out. It did taste weird. It tasted kind of like house cleaner."
In a video posted on Snapchat, Williams explained she sampled a dish of chicken and rice offered on a 'doggy menu' at her hotel.
"I force-swallowed it, said the 34-year-old American. "I don't know what they put in these dog foods, but Chip liked it.
"I don't think it's consumable for humans. They should have wrote that! So now I feel really sick. It was just a spoonful, but I don't feel so good."
Williams defeated McHale 7-6 (9-7) 6-1 and set up a meeting with Svetlana Kuznetsova, who beat fellow Russian Daria Gavrilova, in the last eight.