Coach Stephen Betham on Thursday named the same line-up that eased to a comfortable 39-10 win over Italy in Nelspruit last week for the match-up with the Springboks at Loftus Versfeld.
There is only one change among the substitutes where flanker Alafoti Faosilva replaces Piula Faasalele, who won his first cap off the bench last weekend, a Samoa Rugby Union statement said.
Samoa beat Scotland 27-17 in their first game of the competition in Durban on June 8 and followed that up with five tries against the Italians last Saturday.
Samoa have lost all seven previous tests against South Africa but pushed the Boks close in a 13-5 setback at the 2011 World Cup in New Zealand in their last meeting.
Teams:
Samoa:
15. James So'oialo, 14. Alapati Leiua, 13. Paul Williams (captain), 12. John Leota, 11. Alesana Tuilagi, 10. Tusiata Pisi, 9. Jeremy Sua, 8. Taiasina Tuifua, 7. Jack Lam, 6. Ofisa Treviranus, 5. Daniel Leo, 4. Teofilo Paulo, 3. Census Johnston, 2. Wayne Ole Avei, 1. Sakaria Taulafo
Substitutes: 16. Ti'i Paulo, 17. Logovii Mulipola, 18. James Johnston, 19. Kane Thompson, 20. Junior Poluleuligaga, 21. Brando Vaaulu, 22. Seilala Mapusua, 23. Alafoti Faosiliva
South Africa:
15. Willie le Roux, 14. Bryan Habana, 13. JJ Engelbrecht, 12. Jean de Villiers (captain) / Jan Serfontein, 11. Bjorn Basson, 10. Morné Steyn, 9. Ruan Pienaar, 8. Pierre Spies, 7. Willem Alberts / Siya Kolisi, 6. Francois Louw, 5. Flip van der Merwe, 4. Eben Etzebeth, 3. Jannie du Plessis, 2. Adriaan Strauss, 1. Tendai Mtawarira
Substitutes: 16. Bismarck du Plessis, 17. Trevor Nyakane, 18. Coenie Oosthuizen, 19. Juandre Kruger, 20. Siya Kolisi / Marcell Coetzee, 21. Piet van Zyl, 22. Pat Lambie, 23. Jan Serfontein/ Juan de Jongh