Hey big-earner! Serena powers to top spot

No wonder Serena Williams had a smile on her face after partnering her sister Venus to victory in the Australian Open women's doubles today.

Not only is the world No 2 also through to her 13th Grand Slam singles final – she faces Dinara Safina here tomorrow – but she is about to become the highest earning sportswoman of all time.

While Maria Sharapova remains a higher annual earner thanks to her off-court activities, no sportswoman in the world can match Williams in terms of prize money won. In reaching both the singles and the doubles finals here the younger of the Williams sisters took her career earnings to $22,725,475 (about £15.98m).

That takes her $580,740 past Lindsay Davenport's total prize money and $152,283 clear of the golfer Annika Sorenstam. Davenport overtook Steffi Graf's prize money record last year, the German having passed Martina Navratilova's mark 10 years earlier.

Victory in today's doubles final added another $Aus112,500 (about £50,975) to her bank balance – Serena and Venus beat Daniela Hantuchova and Ai Sugiyama 6-3, 6-3 – while beating Safina tomorrow would be worth an additional $Aus1m (£453,460). She was already assured of the same sum for reaching the final.

"I remember earning my first cheque of $240 at Quebec City in 1995 and while I knew that I could have a great career in tennis, I could not have imagined or dreamed of all of this," Williams said.

"It's amazing how much women's tennis has grown since I joined the Tour 14 years ago. I am very proud to have reached this milestone for me, my family and all women athletes out there. This achievement really shows that if you put your mind to it, you can achieve anything."

The female singles champions at the four Grand Slam tournaments now receive the same prize money as their male counterparts, although the rewards for men are generally higher during the rest of the year. A woman has finished as the top earner in tennis only three times, in 1984 (Navratilova), 1991 (Monica Seles) and 2003 (Kim Clijsters).

Today's sums dwarf the rewards that were on offer in the early days of Open tennis. In 1971 the total prize money for 19 events on the women's tour was $309,100 (about £218,000). This year the women will compete at 55 events for more than $86m (£60.5m).

Billie Jean King became the first woman to earn more than $100,000 ((£70,000) in a single season in 1971 (in 2008 143 women earned more than $100,000) and Chris Evert became the first past the career $1m mark five years later. Navritilova was the first past $10m in career earnings (in 1986) and $20m (in 1994).

Navratilova was also the first woman to earn more than $1m in a single season (1982) and the first past $2m (1984). Martina Hingis passed $3m (in 1997), Clijsters $4m (2003) and Justine Henin $5m (2007).

At 27 Williams still has plenty of money-earning years ahead of her. Some questioned her future when she went two years without a Grand Slam title after winning here in 2005, but her triumph at this tournament in 2007 signalled a new phase of her career. She has since reached the final at Wimbledon, losing to sister Venus, and won the US Open for the third time.

Williams has won nine Grand Slam titles and is one of only six women in the Open era, alongside Margaret Court, King, Evert, Navratilova and Graf, to have won all four Grand Slam events. She has yet to win all four in a calendar year but achieved the "Serena Slam", holding all four titles when she won here in 2003. She has also partnered her sister to two doubles gold medals at the Olympic Games, in Sydney in 2000 and in Beijing last year.