Former world No.1 and record Grand Slam winner, Serena Williams has again emerged as Forbes’ highest-paid female athlete for the fourth year in a row after she earned $29.2 million, including $4.2 million in prize money.

Williams made the money after returning to the WTA Tour following the birth of her daughter, Olympia, in September 2017.

Williams continues to expand one of the most robust endorsement portfolios in sports, adding Pampers, Axa Financial and General Mills to her roster. They join more than a dozen other brands like Nike, Beats, Gatorade and JPMorgan Chase.

The 23-time Grand Slam champ scores highly across all demographics, and only Tiger Woods and Tom Brady have higher levels of awareness among athletes with U.S. consumers.

Williams’ $225 million estimated net worth makes her the only athlete on Forbes’ list of America’s Richest Self-Made Women.

Young Japanese tennis star, Naomi Osaka, 21, came in second position this year with $24.3 million.

Next on the list is Germany’s Angelique Kerber who made £9.7m ($11.8m)

The highest-placed athlete from another sport was United States footballer Alex Morgan in 12th. She earned £4.75m ($5.8m) US dollars and all of the money was made through endorsements.

SEE THE FORBES TOP 15 EARNERS

1. Serena Williams (tennis)

Total Earnings: £24m ($29.2m)

Prize Money: £3.4m

Endorsements: £20.5m

2. Naomi Osaka (tennis)

Total Earnings: $24.3 million

Prize Money: $8.3 million

Endorsements: $16 million

3. Angelique Kerber (tennis)

Total Earnings: £9.7m ($11.8m)

Prize Money: £4.3m

Endorsements: £5.4m

4. Simona Halep (tennis)

Total Earnings: £8.4m ($10.2m)

Prize Money: £5.1m

Endorsements: £3.3m

5. Sloane Stephens (tennis)

Total Earnings: £7.9m ($9.6m)

Prize Money: £3.3m

Endorsements: £4.5m

6. Caroline Wozniacki (tennis)

Total Earnings: £6.2m ($7.5m)

Prize Money: £3.3m

Endorsements: £2.9m

7. Maria Sharapova (tennis)

Total Earnings: £5.8m ($7m)

Prize Money: £825K

Endorsements: £4.9m

8. Karolina Pliskova (tennis)

Total Earnings: £5.1m ($6.3m)

Prize Money: £3.8m

Endorsements: £1.4m

9. Elina Svitolina (tennis)

Total Earnings: £5m ($6.1m)

Prize Money: £3.8m

Endorsements: £1.2m

10 (tie). Venus Williams (tennis)

Total Earnings: £4.8m ($5.9m)

Prize Money: £740K

Endorsements: £4.1m

10 (tie). Garbine Muguruza (tennis)

Total Earnings: £4.8m ($5.9m)

Prize Money: £1.9m

Endorsements: £2.8m

12. Alex Morgan (football)

Total Earnings: £4.7 ($5.8m)

Salary: £205K

Endorsements: £4.5m

13 (tie). P.V. Sindhu (badminton)

Total Earnings: £4.5m ($5.5m)

Prize Money: £500K

Endorsements: £4.1m

13 (tie). Madison Keys (tennis)

Total Earnings: £4.5m ($5.5m)

Prize Money: £2.5m

Endorsements: £2m

15. Ariya Jutanugarn (golf)

Total Earnings: £4.4m ($5.3m)

Prize Money: £3.3m

Endorsements: £2 million