Naomi Osaka has been a Grand Slam tennis champion and No. 1 in the WTA rankings. And now she’s No. 1 on another list: sports’ top-earning female athlete. Osaka was the top-earning female athlete over the past 12 months, according to forbes.com . Osaka, 22, earned $37.4 million from endorsements and prize money, $1.4 million more than Serena Williams, in that span, Forbes says. Osaka’s total is a one-year record for a female athlete, topping the $29.7 million earned by Maria Sharapova in 2015.“To those outside the tennis world, Osaka is a relatively fresh face with a great backstory,” David Carter, a sports business professor at USC’s Marshall School of Business, tells Forbes . “Combine that with being youthful and bicultural, two attributes that help her resonate with younger, global audiences, and the result is the emergence of a global sports marketing icon.”Osaka, who has a Japanese mother and a Haitian-American father, broke out in tennis with back-to-back Grand Slam titles at the 2018 U.S. Open and the 2019 Australian Open. Her family roots are crucial to her endorsement stardom, Forbes says. She was born in Japan. When she was 3, she and her family moved to the United States, settling on Long Island and then heading to Florida.Osaka maintains dual citizenship but chose to represent Japan ahead of the 2020 Summer Olympics in Tokyo, now postponed to 2021 because of the coronavirus pandemic. Forbes says the decision made her an even hotter commodity for Olympic sponsors such as Procter & Gamble, All Nippon Airways and Nissin Food Products, which signed endorsement deals with Osaka to use her around marketing for the Games.Williams, 38, had led the earnings way among women each of the past four years, with annual pre-tax income ranging from $18 million to $29 million, Forbes says. The 23-time Grand Slam champion has collected almost $300 million during her career from endorsements, it says.Osaka is No. 29 overall and Williams No. 33 on Forbes ’ annual list of the 100 top-earning athletes for the past 12 months. Forbes says its full 2020 list is set for release next week.The highest-paid female athlete every year since Forbes started tracking the data in 1990 has been a tennis player. In Forbes ’ rankings, the last top-earning female athlete outside of Williams and Sharapova was Serena’s sister Venus in 2003. Tennis players are the only women to rank among Forbes ’ 100 top earners in sports since 2012: Sharapova, Li Na, Serena Williams and now Osaka.