The South African squad of Roland Schoeman, Lyndon Ferns, Darian Townsend and Ryk Neethling clocked 3 minutes and 13.17 seconds to triumph over the Netherlands (2nd) and the US team (3rd).
The triumph was South Africa's fourth gold medal since re-admission to the Olympics in Barcelona 1992, adding to the two won by swimmer Penny Heyns in Atlanta and the marathon gold by Josia Thugwane at the same Olympics.
