The scores were 2-6, 6-2, 6-2.
It is Bartoli's second career title and her second this year, following on her victory in Auckland, New Zealand.
"Aiko was well-prepared and moving fast, especially in the first set," Bartoli said. "I tried to make her run more in the second set, and she looked more and more tired. Good first serves were the key to my victory today. I was able to play aggressively. I was able to take advantage of her second serves as well."
Nakamura was attempting to get Japan its first championship since Ai Sugiyama won at Gold Coast in the first week of the 2004 season.
She is ranked No. 89 and was a wild-card entry in this tournament.