Fourth-seeded Frenchwoman Caroline Garcia was forced to retire with a back injury during her match against compatriot Alize Cornet in the first round of the Brisbane International on Sunday.
Garcia, who enjoyed a breakthrough season in 2017 when she reached a career-high world ranking of eight, took the first set 6-3 with relative ease.
But Garcia began to struggle with her service game and Cornet stuck back to take the second by the same score.
Garcia then called for the trainer and had extensive treatment for a lower back problem.
She returned to the court but after one serve retired in tears, handing 2017 runner-up Cornet a ticket to the second round.
“I always had some issues with my back,” Garcia said later.
“At the beginning of the match I felt a pain in my lower back and it was different than it is normally.
“It was getting worse and worse and in the end I couldn’t really move.”
She said she was uncertain how the injury would affect her Australian Open plans.
“I will take some rest and with the physio I will improve as fast as I can,” she said. “But right now I don’t know much.”
Cornet will meet Croatian Mirjana Lucic-Baroni in the second round after the 35-year-old downed German Tatjana Maria 6-4, 4-6, 6-0.
Former US Open finalist Samantha Stosur continued her miserable run in her home tournament when she was bundled out by Latvia’s seventh seed Anastasija Sevastova 6-1, 6-3.
Stosur has now failed to get past the second round in eight attempts in Brisbane.
There was a minor upset in the men’s draw when former Brisbane finalist Alexandr Dolgopolov of Ukraine downed sixth seeded Argentine Diego Schwartzman 6-4, 7-6 (7/3).