Emma Raducanu is out of the Australian Open after China's Yafan Wang beat her in three sets as the Briton struggled with sickness at the end of the match.
Raducanu, who made her return to tennis two weeks ago after missing most of the 2023 season to have three surgeries, had fought back from a set and a break down to force a deciding set.
But she struggled physically - and appeared to have breathing difficulties, clutching at her chest and abdomen before calling the trainer after two games.
She had her blood pressure checked and took some pills before resuming, and she battled hard to try to turn the match around.
But Wang took advantage to win 6-4 4-6 6-4 and go through to the third round.
There is now no more British representation in the women's singles.
"I think I just had a bit of a stomach bug beforehand," she said. "Now I feel a little bit better. I had some time.
"During the match, third set I was 30-0 up serving. Then all of a sudden I just felt so sick, just really weak and nauseous. Throughout the third set I think everyone could see it was a bit of a battle.
"Like physically, body-wise, I felt fine. It was more I was throwing up in my mouth. Then after the match, it came out. Now I'm okay. I'll get over it. It just sucks with the timing. I was actually feeling good about my tennis. Mentally, I don't know why, I just felt really composed the entire time.
"Even in the first set when I was making a ton of errors with the wind, I kind of always had this feeling that I was coming back, just tidy up the errors. I felt pretty composed throughout."
It was only the former US Open champion's fourth match since returning from eight months out and three surgeries.
The 21-year-old had come into the tournament stating she was a "better player" than before her surgeries and looked good in her straight-sets win over Shelby Rogers in the first round.
However, she will be concerned about her fitness and the lack of power from her forehand which was a big strength when she won the 2021 US Open title.
Raducanu's exit followed those of Katie Boulter and Jack Draper and means Cameron Norrie, who battled from two sets down earlier to beat Giulio Zeppieri, is the only British player through to the third round.
Norrie completed an incredible comeback from two sets down to beat Giulio Zeppieri 3-6 6-7 (4-7) 6-2 6-4 6-4.
The match featured two rain delays and multiple medical timeouts for Norrie as he dug deep to set up a last-32 clash with world No 11 Casper Ruud.
Draper wasn't able to join Norrie in the next round as Tommy Paul got the better of the Briton 6-2 3-6 6-3 7-5.
British number one Boulter lost 6-3 6-3 to 12th seed Zheng Qinwen in windy conditions at Melbourne Park.