Australia stunned South Africa 21-6 at Brisbane's Lang Park on Saturday to stall the world champions' bid to wrap up the Tri-Nations.
The Australians ended a frustrating run of four straight losses in the series with an unexpected but deserving win over the previously unbeaten Springboks.
Outside centre Adam Ashley-Cooper and teenage fullback James O'Connor both scored late second-half tries to seal the win for the Wallabies, who had three earlier tries disallowed by the match referee.
Flyhalf Matt Giteau chipped in with two penalties, a conversion and a drop goal while South Africa's points all came from the boot of flyhalf Morne Steyn, who landed a drop goal and a penalty in the first half.
The result breathed new life into a championship that had seemed certain to go to South Africa after they won their first four matches of the series to lead New Zealand by nine points.
Saturday's 15-point loss has suddenly opened the way for the All Blacks to pinch the title if they win their last two matches and get at least one more bonus point than the South Africans.
Best series performance
The Australians were already out of the running for the title after losing three of their four matches by seven points or less, but silenced their critics with their best performance of the series.
They led 9-6 after a tryless first half, then piled on 12 unanswered points in the second term.
Both sides had early tries disallowed. Australia winger Lachie Turner looked to have scored in the right corner but the video referee ruled he had lost the ball when he was hit by a diving tackle.
The Springboks thought they had scored a try when flanker Heinrich Brussow crashed over just before the break but English referee Wayne Barnes ruled the last pass from scrumhalf Fourie du Preez was forward.
Australia had another two tries disallowed by the video referee early in the second half as both teams defended desperately.
Genia was denied a touchdown after he took a quick tap only for replays to show du Preez had managed to rip the ball from his grasp just before he planted it down.
Then Giteau missed out on a try when he was judged to have put his foot into touch just as he was diving into the corner.
The Wallabies finally crossed for a legitimate five-pointer when inside centre Berrick Barnes put Ashley-Cooper into a hole and he sprinted 20 metres to score in the 63rd minute.
O'Connor put the result beyond doubt with an opportunist's try in the 76th minute, scooping up a loose ball and dashing away to score.