Davenport joined Martina Navratilova, Chris Evert, Steffi Graf and Gabriela Sabatini as the only three-time winners at Amelia Island.
"This is a huge win," Davenport said. "Whenever I can win on clay against a really tough tournament, it gives me a lot of excitement."
Davenport has now appeared in 83 singles finals, winning 47 titles over 13 years. The American says this will be her farewell year on tour.
Farina Elia benefited from Serena Williams suffering a twisted ankle in their quarterfinal match.
"I really fought hard today," Farina Elia said. "I played really my best game. I did what I could today. I think Lindsay came up with unbelievable points in a very important game. All the time I had break points she came up with a serve, an ace."
The Italian is now 3-10 in career singles finals.
In the doubles final the Australian team of Bryanne Stewart and Samantha Stosur won their second title as a team this year, defeating Kveta Peschke and Patty Schnyder 6-4, 6-2.
"I don't know if we really let them play the way they wanted to play today," Stosur said. "They weren't really moving that much on the net. We rallied quite well from the baseline."