Playing with the wind at their backs, the Bok Women had Samoa under pressure for most of the first half, making their opportunities count to score four tries in the process and lead by 26-0.
It could have been more had they been more clinical at lineout time and at the breakdowns, where Samoa forced a number of turnovers - a trend that continued in the second half.
However, as had become the norm, the South Africans' scrum was monstrous and they mauled very well, but they also backed that up with patience on attack in the Samoan half, ensuring the scoreboard regularly ticked over.
Janse van Rensburg (flyhalf) stepped a few Samoans to scored the first of her two first-half tries - which she also converted - in the sixth minute, with Catha Jacobs (No 8) beating some defenders out wide five minutes later to make it 12-0.
Samoa then got some possession, but it didn't last long and in the 24th minute, Janse van Rensburg scored from a superb chip-and-gather before adding the conversion for a 19-0 lead.
At the death of the first half, hard-working flanker Lusanda Dumke added her name to the scoresheet by crashing over off the back of yet another dominant scrum to put the hosts in firm control at the break.
Despite South Africa continuing their dominance upfront, the second half descended into a bit of an arm wrestle, with no points scored until the 72nd minute, when Samoan captain Sui Pauaraisa (flanker) scored under the uprights, five minutes after they lost Lulu Leuta (replacement hooger) to the sin bin for a dangerous tackle in SA fullback Byrhandre Dolf, who was a menace on the counter-attack and looked dangerous with ball in hand.
Janse van Rensburg, the Player of the Match, scored her third try four minutes from the end as the South Africans again showed their awareness on attack after a brilliant run from Piwokuhle Nyanda (inside centre), before Samoa's replacement lock Faalua Tugaga went over, only for the try to be disallowed due to obstruction.
Springbok Women 33 (26) - Tries: Libbie Janse van Rensburg (3), Catha Jacobs, Lusanda Dumke. Conversions: Janse van Rensburg (4).
Samoa 7 (0) - Try: Sui Pauaraisa. Conversion: Bella Milo.