Is Serena Williams better than Steffi Graf?

Serena Williams allowed herself a moment to savor a third straight US Open win last week, but only a moment.

Just three hours after securing her 18th grand slam title with a dominating 6-3, 6-3 win over Denmark's Caroline Wozniacki, the World No 1 soaked up the accolades and applause and then admitted that she was already thinking about number 19 and third spot on the all-time list now held by Helen Wills Moody.

"I am thinking 19," said Williams, who shares fourth on the list with Chris Evert and Martina Navratilova. "Hasn't even been three hours and I have already mentioned 19. Oh, gosh, but not 22. I'm taking it one at a time."

Williams will celebrate her 33rd birthday later this month and clearly has plans to celebrate many more grand slam titles as she climbs further-and-further up the rankings.

Moody, at number 19, is the next target but just ahead sits Steffi Graf on 22 and just ahead her is the great Margaret Court who tops the list with 24.

Italian tennis ace Francesca Schiavone has said that she regards Serena Williams better than Steffi Graf after she drew within four Grand Slam titles of the former German great's Open-era record.

Schiavone described Williams as special after the American bagged her 18th Grand Slam title at the US Open.

The 2010 French Open champion said that sometimes she thinks Williams is the best there has ever been, and added that the American is special, Sport24 reported.

Schiavone said that when there was Navratilova, Graf, she was thinking who can come and better than this and Williams arrived and it was her.