South Africa built a 22-point lead within 18 minutes, then failed to score again while Australia crossed the tryline six times for a first victory in Johannesburg since 1963.
“Obviously, everyone is ashamed, no one is proud of themselves,” Erasmus told a press conference in Cape Town.
“It only strengthens our cohesion and our desire to do well. You do not learn anything from a match like that – when you see what we sometimes handed them on a plate.”
Australia have also been hit by injuries with wing Dylan Pietsch (broken jaw) and prop James Slipper (concussion) flying home after the Ellis Park Test.
Coach Joe Schmidt has called up three replacements, wing-centre Filipo Daugunu, centre Hamish Stewart and prop Rhys van Nek, as cover.
The Wallabies hope captain and No 8 Harry Wilson, who scored two tries in Johannesburg before limping off injured, will be fit for Cape Town.