South Africa continued their dominance in this year's Rugby Championship as they clinched an 18-12 victory over New Zealand in Cape Town on Saturday.

Having trailed by six points heading into the break, the hosts rallied to record a fourth consecutive win over the All Blacks and lift the Freedom Cup for the first time in 15 years.

New Zealand started brightly, with their dominance rewarded by the boot of Damian McKenzie after Jasper Wiese had been sent to the sin bin.

McKenzie converted his second penalty just before the half-hour mark as the Springboks saw some uncharacteristic errors punished. 

Handre Pollard's penalty failed to change the sway of momentum, with McKenzie's third conversion of the half giving the All Blacks the advantage at the break. 

But an immediate response transpired after the interval as Siya Kolisi burst over the tryline, with Pollard's conversion handing the Springboks the lead for the first time.

Sacha Feinberg-Mngomezulu extended South Africa's advantage, but McKenzie's fourth and final penalty of the encounter closed the gap once again. 

However, the hosts sealed the win when Malcolm Marx powered over for a try six minutes from time to see the Springboks close in on the title.

Data Debrief: Cape Town comforts

This is the first time since 1949 that South Africa have won four straight Tests against their great rivals New Zealand.

They have also now won four straight Tests in Cape Town, and that is despite trailing at half-time in three of those four matches. 

New Zealand, meanwhile, have lost three of their last four Tests, having only suffered one defeat across their previous nine matches.

Malcolm Marx scored two tries in the second half to lead South Africa to a 30-12 victory over Australia in rainy Perth.

After a tight first half, the Springboks asserted their dominance to make it two wins from two in the Rugby Championship ahead of their meeting with New Zealand next week.

Noah Lolesio's penalty gave Australia the early lead, but they could not hold onto it for long as Sacha Feinberg-Mngomezulu equalised moments before Aphelele Fassi latched onto a long kick to touch down the first try.

Lolesio slotted in two more kicks only to miss another on the stroke of half-time that would have given the Wallabies the lead.

They were punished for it after the break as Marco van Staden and Malcolm Marx twice touched down to maintain South Africa's perfect start.

Though it was a marked improvement for the Wallabies from their opening-day performance in Brisbane, Joe Schmidt still has work to do to get them ready for Argentina next weekend. 

Data Debrief: Springboks extend Australian run

South Africa have now won each of their last three Test matches against the Wallabies in Australia. The last time they recorded a longer such winning run was a four-match span from July 1971 to July 1993.

Though Australia have suffered back-to-back defeats, they showed more of a fight. Last week, it took them 75 minutes to score, compared to just three this time around.