Sydney: Albie Morkel provided some more late fireworks to help South Africa beat Australia by three wickets in Sydney, and put them 2-1 ahead in the series.
The Proteas achieved the highest run chase at the SCG, overhauling Australia's 269 with 21 balls to spare to win by three wickets and take a 2-1 lead in the five-match series.
The home side must now win the Australia Day clash at the Adelaide Oval on Monday to avoid a series defeat.
Tonight's victory was a deserved one for the Proteas, who did well to restrict Australia after it had looked set to score in excess of 300 at one point.
Opener Gibbs then hammered 64 off 52 balls to put South Africa well and truly on its way, receiving strong support from Jacques Kallis (60 off 72).
Morkel did what he does best, coming in at number eight and profiting from the powerplay by crushing 40 off only 22 deliveries.
The all-rounder smoked 30 of his runs in boundaries, with a six and two fours heaved off the 46th over bowled by Nathan Hauritz, playing his first one-day international since 2003.
Morkel went down trying to smash a six for victory, but the damage had already been done and captain Johan Botha was left to hit the winning four.
Mark Boucher remained unbeaten on 31, providing the perfect foil for the likes of Morkel by refusing to give his wicket away by playing a rash shot.
Australia paid heavily for dropped catches, with both Gibbs and Hashim Amla put down in the first over bowled by Shaun Tait before both batsmen had scored.
Tait himself grassed a difficult chance in the outfield when Morkel was on 10.
"[There were] lots of mistakes, whether it be with the bat not capitalising on partnerships, or dropping catches early on," Australian captain Ricky Ponting said.
"A couple of mistakes from us were probably the difference in the game."
Botha led by example during Australia's innings, taking a fine 3 for 32 from his 10 overs to peg back what had been a rampant home outfit.
David Warner justified his inclusion and ensured he is not a one-hit wonder, plundering his maiden one-day half-century in front of his home fans.
Warner's 60-ball 69 and Shaun Marsh's 43 laid the platform for a big score, but as has so often happened this summer, the momentum quickly shifted.
David Hussey (36), James Hopes (33) and Ponting (29) all got starts but failed to go on with it and the rest of the order failed to make an impact.
Such was Australia's start that it was a crime it did not bat out its 50 overs, falling four deliveries short.
South Africa's reply was swift with the recalled Mitchell Johnson, rested for the first four limited overs matches, coming in for some severe punishment.
Johnson was the pick of the Australian attack during its Test series defeat but was rusty tonight and was taken for 71 off nine overs for just one wicket.
Hauritz took two wickets but went for 60 off nine while Tait also conceded almost a run a ball.
Nathan Bracken justified his status as the world's top-ranked one-day bowler, finishing with a miserly 1 for 29 off his nine overs.
At conceded only 10 runs from his first six overs.