The fourth seed won her first title this year and had little trouble seeing off the third seed in what is Collins' final season on the tour.

"Danielle, you've had the most incredible few weeks," Keys said.

"I've absolutely loved cheering you on and watching you beat basically everyone who stood in your way. It's been amazing to see that."

Keys broke serve three times in the opening set, winning five games in a row to take the first set and began the second in much the same vein to hold a 3-1 lead before Collins made her first break of serve.

Her chance of a comeback was short-lived, however, as Keys immediately broke back to lead 4-2 and wrapped up the title win with a third break.

"What a special week to play one of my long-time friends, Madi. We've known each other since we were 10 years old," Collins said.

"I never like losing in the finals, but if I'm gonna lose to someone, I don't mind losing to you, cause you know, we're American buddies."

Keys, 14th seed at Roland Garros will play Mexican Renata Zarazua in the first round of the French Open which begins on Sunday, while Collins, seeded 11th, will face compatriot Caroline Dolehide in her opening match.