In a solid top eight battle, the Tricolours looked superior from the outset, running in three early tries to set up an impressive victory.
The entire Roosters forward pack lifted for this clash with the big men constantly generating impressive metres.
Full of confidence after making his NRL debut just weeks ago, Samisoni Langi came out firing for the visitors, registering the first six points of the match when he converted his own solo effort from five metres out early in the first half.
Arguably the most improved player in the team, Shaquille Blair added a second try on the very next set, crashing through the South Sydney line and throwing an unexpected dummy, fooling the fullback to storm over.
It was all the Tricolours as the visitors really started to stamp their authority on the match.
Brendan Elliot added a third when he punched on a dropped bomb and it looked as though the Tricolours were going to run away with it early.
With a lot of local pride on the line, the Rabbitohs hit back after a powerful surge from Duncan Low to put the home side within twelve.
A dubious decision for what looked like a clear obstruction handed South their second just before the break.
Tricolours captain Rhyse Martin was subsequently sent to the bin when questioning the referee's decision.
The home side did well to hold on a man down and added another try as soon as Martin came back on, Togitasi touching down to further extend the home side's lead.
A sneaky grubber that dribbled behind the Tricolours line set up the Rabbitohs third to put them within eight.
Showing exactly why he was chosen in the Holden Cup Team of the Year, John Asiata simply put his head down and burrowed over the Souths line to seal a great result for the Tricolours.