Tennis: Finally, Serena Williams is the world’s highest paid female athlete

Serena Williams of the U.S. shouts as she plays Spain's Garbine Muguruza during their final match of the French Open tennis tournament at the Roland Garros stadium, Saturday, June 4, 2016 in Paris. (AP Photo/Michel Euler)

Serena Williams has dominated women's tennis over the course of her career, winning 21 Grand Slam titles, racking up more than $77 million in prize money and earning the title of Associated Press Female Athlete of the Year four times, including 2015.

But for 11 years in a row, rival Maria Sharapova outranked her as the world's highest-paid female athlete. The Russian star has endorsed everything from sportswear and sports cars to watches and cosmetics and filtered spring water. But Williams was better on the court, with a 19-2 record against Sharapova, beating her in every meeting since 2005.

Although Williams recently finished second to Garbiñe Muguruza in the French Open, she has taken first in a more elusive challenge. According to Forbes, Williams has finally eclipsed Sharapova as the highest paid woman in the world of sports with earnings of $28.9 million in the past 12 months. Endorsements account for $20 million of that sum.

What were the factors that filled all those precious metal plates, bowls and jugs with greenbacks? Two reasons stand out.

First, Williams, 34, has remained a fierce competitor. In 2015, she won $10,582,642 and went 53-3 in singles competition with three major singles titles. In addition to winning the AP award, she was named Sports Illustrated's Sportsperson of the Year. This year she has gone 24-4 in singles competition and reached the final at both Roland Garros and the Australian Open.

All that winning makes Williams an attractive pitch woman. She joined Stephen Curry as a part of JPMorgan Chase's "Chase Mastery" campaign. She continued a profitable relationship with Gatorade and pitched her own clothing line as part of an equity deal with Home Shopping Network.

From Forbes: "Her late-career tear has made Williams a compelling figure for marketers. She ranks second among active athletes, behind only LeBron James in the U.S., on Repucom's CelebrityDBI, which tracks consumer perceptions of celebrities based on awareness, as well as seven attributes. Her 89% awareness level ranks in the top 3% of the nearly 4,000 celebrities Repucom follows, and she scores highly on the aspiration and influence attributes in particular."

Secondly, Sharapova admitted in March she tested positive for meldonium at the Australian Open. Sponsors including Nike and Porsche suspended their ties with Sharapova and TAG Heuer and American Express opted not to renew deals with her. Avon, Evian and Head all stayed by her side.

All of that bumped Sharapova down to No. 2, where she collected $21.9 million. Fighter Ronda Rousey ($14 million) ranks third, driver Danica Patrick ($13.9 million) is fourth and fellow tennis player Agnieszka Radwanska ($10.2 million) round out the top five.