The Wallabies have pulled off a miraculous comeback to open the Rugby Championship in grand style with a famous 38-22 triumph over the world champion Springboks in South Africa.

If this wasn't the Wallabies' greatest ever victory, it was most certainly their most improbable after Joe Schmidt's revitalised outfit recovered from 22-0 down in Johannesburg.

With skipper Harry Wilson, fullback Tom Wright and veteran flyhalf James O'Connor starring, the Wallabies piled on four unanswered second-half tries to record Australia's first victory over the Springboks at altitude since 1963.

The stirring success came at a cost, though, with heroic No.8 Wilson escorted off with a knee injury after touching down for his second try and winger Dylan Pietsch sustaining a suspected broken jaw.

Minutes after crossing for Australia's opening try, Pietsch came off second best in a collision with Springboks captain Siya Kolisi.

But the Wallabies will otherwise savour a truly incredible win at Ellis Park.

The two-time defending world champion Springboks looked set to consign Australia's last-up victory over the British and Irish Lions to a distant memory when they raced out to their 22-0 lead inside 18 minutes.

Winger Kurt-Lee Arendse bagged the opening try after just 94 seconds.

Unable to cope with the home team's awesome skill and firepower, the Wallabies conceded a second when centre Andre Esterhuizen completed the slickest of raids in the 12th minute.

Kolisi palmed off Fraser McReight at the back of a ruck to continue the better-than-a-point-a-minute scoring blitz with South Africa's third try before the Wallabies finally found their second wind.

Pietsch put Australia on the board after 28 minutes when he finished off some nice lead-up work from O'Connor and centre Len Ikitau, who handled twice in the movement.

Pietsch lasted only two more minutes before his head caught the shoulder of Kolisi while trying to stop South Africa's rampaging No.8.

Trailing 22-5 at the break, the Wallabies needed something special to conjure a famous victory.

Angus Bell delivered first, the replacement prop's deft short putting skipper Harry Wilson over two minutes into the second half before Joseph-Aukuso Suaalii intercepted a cut-out pass from Springboks flyhalf Manie Libbok to pull the Wallabies within three points of the hosts.

Then the unthinkable happened.

The Wallabies hit the lead for the first time when Wright broke free from inside his own half to put Wilson over for his second try to give the Wallabies a shock lead.

Playing his first Test since 2022 and some 17 years after debuting, O'Connor found Max Jorgensen with a beautiful left-to-right long ball before the winger did the rest in another magical long-range strike for Australia.

Turning defence into scintillating attack, Wright sped 80 metres to score the game sealer with five minutes remaining, leaving South African fans silently shellshocked.