For Serena Williams, less is more.

The 33-year-old's sixth Australian Open title on Saturday took her to a career total of 19, one better than Chris Evert and Martina Navratilova in the all-time list.

And though she is the second-oldest woman to win a grand slam singles title (Navratilova holds that mark), if the American can stay fit, it seems inevitable that she will add to that tally.

Steffi Graf, who holds the Open era record with 22, posted a message on her Facebook page saying it was a privilege to watch her play and compete.

"History will prove we are witnessing a great champion in a unique time in her career whose impact on the sport has yet to be fully written. Well done Serena."

Quite how Graf will feel if Williams goes on to equal or pass her in the all-time list remains to be seen but at this stage in her career, grand slams are what makes her tick and it's hard not to see her reaching 20 and going beyond.

"She could win one or two more this year," said Evert, who said she'd long resigned herself to being overtaken, and was delighted to see it happen.

With the likes of Maria Sharapova, her victim in the Melbourne final, Wimbledon champion Petra Kvitova, a rejuvenated Victoria Azarenka and others all threatening, Williams knows nothing can be taken for granted.

And as she heads toward her mid-30s, Williams says she plans to cut down on her schedule, focusing on the other three slams, the French Open, Wimbledon and the US Open.

Having won in Melbourne despite suffering from a fever and a cough which forced her to vomit at one stage during the final, Williams' will to win shows no sign of dimming.

Having taken a long time to get from grand slam No 17 to 18, she has now won back to back titles and another "Serena slam" of four straight titles, as she managed in 2002-3, is within the realms of possibility.

And having lost early at the French Open and Wimbledon last year, the motivation to improve is there.

"When I think about Paris, I don't think about 20. I just think about winning there," Williams told reporters. "It's the one slam I don't have more than two titles. I only have two there.

"So I think now that I got this under my belt, I'm a little more comfortable with my ranking now. Now I can really move. I did so bad last year at Roland Garros and Wimbledon as well so those are the two I really have my eye on, because I would like to do better at those. And I know I can do better."

For Sharapova, her loss to Williams was an extension of the American's domination of their "rivalry", having not lost to the Russian since 2004.

But despite the disappointment of going so close - the second set of her 6-2, 7-6 defeat included some outstanding tennis - Sharapova still believes she can add to her tally of five grand slam titles.

"Yes, I haven't won against her many times, but if I'm getting to the stage of competing against someone like Serena, I'm doing something well," she said.

"I'm setting up a chance to try to beat her and it hasn't happened. I'm not just going to go home without giving it another chance.

"If I'm getting to the finals of Grand Slams and setting myself up to play a match against Serena...I'm happy to be in that position. I love the competition. I love playing against the best, and at the moment she is."