Davenport finished off Kuznetsova in 59 minutes, winning on her second match point.
"I sprained it a little bit the other day," Davenport said of her ankle injury. "It was just a little bit swollen. ... I kind of jammed it on one shot. Hopefully, it will have a little time to get better."
Davenport, a finalist last year in the Australian Open and Wimbledon, said she is playing better now than she was in 2000, when she captured her last Grand Slam singles title at Melbourne Park.
"I feel like I'm playing some of my best tennis," Davenport said. "It's unfortunate that all the other girls are playing so much better. This is the highest level we've ever competed at."