Naomi Osaka had the biggest win of her career when she beat Serena Williams in the 2018 U.S. Open.

From prize money and endorsements, Osaka earned $1.4 million more than Williams — making her the highest-paid female athlete in history.

Forbes reports that Williams, making between $18 to 29 million annually, was the top earner among professional female athletes for the past four years before being knocked off by Osaka.

Williams comes in at number 33 on the list of 100 highest-paid athletes while Osaka is at 29.

“To those outside the tennis world, Osaka is a relatively fresh face with a great back story,” said David Carter, sports business professor at USC’s Marshall School of Business.