“After the first quarter, it fell 22-0 after the first quarter,” Schmidt told South African TV channel Supersport.
“We were forced to chase and take some risks, we had some lucky bounces, so we weren’t going to be taken too far.
“But at the same time, I'm very proud of this team. I'm glad to get a little luck, but we're glad to be back. 1963 was a long time ago, so the players are happy.”
Argentina hosts New Zealand in Córdoba later Saturday.
South Africa: NCHE, Marx, Louw; Etzebeth, de Jager; Van Staden, Du Toit, Kolisi (C); Williams, Liebroke; Arendse, Esterhuizen, Kriel, Van der Merwe; Faspi.
Replacers: Mbonambi, Venter, Ntlabakanye, Mostert, Smith; Reinci, Moody, Willem.
Australia: Slippers, Pollard, Tup; Frost, Skelton; Hooper, McReight, Wilson (C); White, O'Connor; Pietsch, Ikitau, Suaali, Jorgensen; Wright.
Alternators: Paenga-Amosa, Bell, Nonggorr, Williams, Gleeson; McDermott, Edd, Keraway.