Bartoli limped off the court in tears after retiring with unseeded Medina Garrigues ahead 4-6, 7-6 (7), 1-0.
The Spaniard argued twice with the umpire as Bartoli took control of the first set. Bartoli had to rally in the second to force a tiebreaker in which she held match point. But Medina Garrigues prevailed 9-7 to lead the match into a third set.
Bartoli began the set with her right ankle taped and lasted only one more game.
"Even if I won match point I don't think I would have been able to play tomorrow," said Bartoli, who also retired in the 2009 final.
The win for Medina Garrigues ended her 18-match losing streak against top-10 players since 2008.