Top seed Marion Bartoli squandered two match points before she had to retire with an ankle injury in her opening match at the Tournament of Champions against Spain's Anabel Medina Garrigues.
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.