Joe Schmidt said he cannot recall ever being involved in a more "bizarre" Test as his Australia side were downed 30-12 by South Africa in the Rugby Championship.

Malcolm Marx touched down twice for the Springboks in rainy Perth to make it two from two in the tournament but the Wallabies were hit by a swathe of injuries.

Front-row pair Allan Alaalatoa and Angus Bell were unable to return for the second half and scrums went uncontested after replacement prop James Slipper failed a head injury assessment.

The Wallabies even went down to 14 briefly when hooker Josh Nasser went off injured, though they did return to a full 15.

Reflecting on the unfortunate series of events, head coach Schmidt told Stan Sport: "It's probably one of the most bizarre games I've ever been involved in.

"In over 100 Test matches that I've been involved in I've never had a situation like that before. It happened so early in the game as well. When Slips got a head knock right after half-time.

"And then we were straight down. And then we played with 14 for a period of time before the officials worked out that we were still entitled to have a full pack because of the HIA.

"But I still am proud of the way that the guys fought their way through that second half. And the way that they stayed in the fight in the first half. It could have been, and I know it could have been as easy to say, but it could have been 12-11 at half-time and that would have been a massive lift for the boys."

Australia are winless through their first two matches, both against the Springboks, and will next face Argentina in La Plata on August 31.

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.