French world No.8 Caroline Garcia has been forced to retire in her Brisbane International first round match with compatriot Alize Cornet.
The fourth seed looked to have control of the contest, when she took the first set 6-3, but Cornet returned the favour to send the tournament opener to a deciding set.
Garcia then took an injury time-out to treat lower back soreness and played just one point in the final set before pulling the pin, Cornet advancing 3-6 6-3 ret after 82 minutes on court.
It is a big blow for Garcia, who was in tears when shaking hands at the net, given her brilliant finish to the 2017 season.
Her ranking surged from 20 to No.8 in the last two months of this year as she beat Ashleigh Barty in the Wuhan Open final, backed up to win the China Open the following week, and finished with a semi-final appearance at the WTA Finals in Singapore.
Garcia hopes the setback won't derail her Australian Open tilt.
"I mean, it's in two weeks, so it's a long time ... with the back it's always complicated," she said.
"Especially mine, it's really something I take care of, so it's kind of surprising for it to show up like this. But we'll do the best that we can."
Cornet, a finalist in Brisbane last January, will play Croatia's Mirjana Lucic-Baroni in the second round.
The 2017 Australian Open semifinalist beat Tatjana Maria 6-4 4-6 6-0.
"The goals are just to win as many matches possible to get back to the top 20, where I used to be," Cornet said.
"But I'm taking it step by step, and having fun and staying injury-free are the most important things."