Number One is Naomi Osaka who held the key when it came to endorsements. Total earnings accrued were at $37.4 million; with $3.4 million being in prize money, $34 million was in endorsements.

The latter included sponsorship with Proctor & Gamble, All Nippon Airways and Nissin; alongside her deal with Nike due to being one of the faces of the Japan representation at the Olympics.

No surprise at two is Serena Williams; with again the legendary American earning a lot through endorsements only just behind Osaka with $36 million overall.

Ashleigh Barty, the current World Number One is one of the only players who has Prize Money larger than endorsements thanks in part to her WTA Finals win. Overall this tallies at $10.1 million and $3 million endorsements; a long way shy of Williams and Osaka.

Simona Halep was fourth with $10.9 million overall. While Bianca Andreescu, the US Open champion was almost level in terms of both barometers having $8.9 million; with $4.9 million prize money and $4 million endorsements.

Garbine Muguruza despite only just returning to form is next up with endorsements standing at $4.5 million due to deals with Adidas, Beats and Rolex; to go alongside her $2.1 million in prize money.

Finalising tennis are Elina Svitolina ($6.4m), Sofia Kenin ($5.8m) and Angelique Kerber ($5.3m) with Alex Morgan, US soccer hero finalising the top ten.

This shows not only the earning potential on the court for female tennis players but also off it with endorsements making a huge difference.