Martina backs Serena

SYDNEY. — World number one Serena Williams shows no sign of slowing down with age and should win more than 20 Grand Slam singles tennis titles, former great Martina Navratilova has said. 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 told reporters in Adelaide where she played in the World Tennis Challenge exhibition yesterday. 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. — SuperTennis.