South Africa have chased down a challenging target of 272 to win the first one day cricket international against Australia at the MCG.
The Proteas took full advantage of their power play in Melbourne for the three-wicket win with just three balls remaining.
With the field up, all-rounder Albie Morkel smashed 40 not out from 18 balls in a match-winning partnership with captain Johan Botha of 51 from 35 balls.
Their stand took South Africa from 221 for seven in the 44th over to 272 for seven and a 1-0 lead in the five-match series.
Australian captain Ricky Ponting, who the toss and chose to bat, believes the new rule favouring the batting team could be a major tactical advancement in one-day cricket.
Friday's match was the first international in Australia where batting sides could nominate a five-over power play, where only two fielders are permitted outside the infield.
The rule was introduced globally late last year, and Australia saw its potential on Friday night.
Opener Shaun Marsh top scored for Australia with 79, while David Hussey scored 50 from 52 balls and Ponting made 46.
South Africa's pursuit was the third-highest successful chase at the MCG, behind the 291 for five which Australia posted to beat New Zealand two summers ago.
So the tourists head to Hobart for game two on Sunday, 1-0 up in the five-match series.