ADELAIDE — Tom-Jelte Slagter of the Netherlands claimed the first stage win of his professional career when he won the third stage of the Tour Down Under Thursday, while Britain's Geraint Thomas retained the overall race lead. Slagter, of the Blanco Pro Cycling team, finished fourth on Wednesday's third stage. His stage win carried a 10 second time bonus which allowed him to close the gap on Thomas to less than five seconds at the midpoint of the six-stage race. Australia's Matthew Goss was second on the 139-kilometer stage between Unley and Stirling and world road racing champion Philippe Gilbert was third. The stage included five laps of a circuit around the town of Stirling in the Adelaide Hills and an uphill finish which tested even the accomplished sprinters. Thomas finished fourth on the stage to remain first overall ahead of Slagter, Javier Moreno of Spain and Ben Hermans of Belgium. “It was pretty tough out there,” Thomas said. “A lot of guys started attacking us three laps out and the boys had to ride really hard. “They did an incredible job today setting a fast tempo all day and I can't thank them enough. “I couldn't manage a podium finish. It would have been nice to get a few more seconds bonus. It was a tough day but that's mission accomplished I guess.” South Africa to re-test over 50 ‘top' cyclists Lance Armstrong's confession has pushed South Africa's anti-doping body to retroactively test blood samples from over 50 top cyclists for EPO. SAIDS says it will re-test samples from cyclists who competed in all major mountain and road races in South Africa last year. The South African Institute for Drug-Free Sport says this will help it discover “if a major EPO doping problem exists in this country.” South Africa's doping body banned David George, one of the country's best riders and a former teammate of Armstrong, for two years last month for EPO use. SAIDS chief executive Khalid Galant says “cycling is being damaged by these high-profile doping cases with a high sense of cynicism existing.” Galant says riders who doped have an opportunity now to confess. WADA disputes Verbruggen claim on doping The World Anti-Doping Agency disputes a claim by former cycling federation leader Hein Verbruggen that discussing suspicious doping samples with athletes was once normal practice in sports. WADA says such a policy “totally contradicts the purpose of an effective anti-doping program.” The agency says it has “no evidence of other international federations ‘discussing atypical blood test results, or other test results' with athletes.” — Agencies