Source: Statista

Following a build-up overshadowed by the Novak Djokovic saga, the actual tennis part of the Australian Open kicked off on Monday. Aside from the year’s first Grand Slam title and plenty of ranking points, the players are also competing for a lot of money down under, with the winner’s purse for both men’s and women’s singles standing at $2.875 million this year.

Tennis is one of the few sports in the world with equal prize money (at least at Grand Slam level), which is part of the reason the sport has dominated Forbes’ list of the highest paid female athletes over the past few years. While this year’s list is more diverse in terms of sports than last year’s edition was, when 9 out of 10 highest-earning female athletes were tennis players, 4 of the 5 top spots are still taken by tennis players.

Naomi Osaka may not have had her best season last year, but she was still the highest-paid female athlete by far, with only Serena Williams coming even remotely close. While making a relatively modest $2.3 million on the actual tennis court (mainly thanks to her Australian Open triumph), Osaka’s off-the-field earnings climbed to $55 million thanks to lucrative deals with brands such as Nike, Louis Vuitton and Tag Heuer.

The discrepancy between on-court performance and off-the-field earnings was even starker in Serena Williams’ case, who only played six WTA Tour events last year and still made $45 million from endorsement deals (e.g. Nike, Gatorade and DirecTV) and numerous other investments.

As the following chart illustrates, Osaka and Williams are in a different league financially compared to their fellow female athletes, but none of them made the top 10 in Forbes’ highest paid athlete list, with Osaka ranked 12th and Williams 28th. Even more notable is the fact that no other female athlete even made the top 50 of the overall list, highlighting the wide gap persisting in terms of athlete pay.