Serena tipped to become undisputed grand slam singles queen
Former champion Martina Navratilova expects Williams to create history
World number one Serena Williams shows no sign of slowing down with age and should win more than 20 grand slam singles titles, says former great Martina Navratilova.
The 57-year-old Navratilova, who won 18 grand slam singles titles and 41 in women's and mixed doubles, is also confident the 32-year-old Williams will equal her singles haul at the Australian Open, which begins next week in Melbourne.
"If she can stay healthy there is no doubt she can go into the 20s. The sky is the limit," Navratilova said in Adelaide where she is playing in the World Tennis Challenge exhibition.
"I know how hard it is once you get to 30. All those little niggling injuries get worse and it's much easier to have an off day.
"But still, she is in her 30s ... she is eager and winning is very contagious - once you get really used to it, you don't want to let go of it."
[Serena Williams] is eager and winning is very contagious - once you get really used to it, you don't want to let go of it
Australia's Margaret Court holds the overall record of 24 grand slam singles titles, while Germany's Steffi Graf won 22 titles in the Open era.