Bali i- Top seed Marion Bartoli squandered two match points before retiring with an ankle injury in her opening match at the Tournament of Champions against Spain's Anabel Medina Garrigues on Friday.
The Frenchwoman, who also retired in the final of the event in 2009, collapsed to the ground after injuring her right ankle soon after the start of the third set.
She was writhing in agony as she received treatment and was eventually helped off the court, surrendering the match 4-6 7-6(7) 1-0.
Bartoli had stood just one point away from advancing but was left frustrated as her erratic serve let her down, prompting her to discard several rackets.
After watching her Spanish opponent save one match point, Bartoli double faulted on the second.
"It happened in the tiebreaker," Bartoli told Reuters. "On one of Anabel's dropshots I really felt my ankle blocked and my whole body went forward on it.
"It started to hurt a few seconds after and when I got the match point on my serve I really struggled to put any weight on my foot. Everything falls apart from there," she added.
"I didn't put any weight on it while I sat in my chair (before the third set) but when I began to walk to serve I realised how bad it was getting. Even if I won the match point I wouldn't be able to play tomorrow.
"It's hard to assess the injury right now but I will have all the time during the off-season to see what happens."
Medina Garrigues will play Sabine Lisicki in the semi-finals after the German recovered from a slow start to beat her Slovak opponent Daniela Hantuchova 7-5 6-2, saving nine of 10 break points against her.
Hantuchova looked sharp from the first ball, and after breaking in the second game she held a further break point to lead 4-0.
But Lisicki's greater firepower began to pull her into the match, and after she levelled at 5-5 she broke serve again and served out the set.
A break for 1-0 gave Lisicki a perfect start to the second set, and she went on to break again for 5-2 on her way to an ultimately comfortable victory.