Johannesburg: Wayne Parnell and Rusty Theron rescued South Africa from a seemingly hopeless position to snatch victory in the second Twenty20 and draw the series 1-1.
Australia had the match all but won with five overs remaining, as South Africa needed 61 with three wickets in hand, an unlikely goal that Parnell and Theron reached with five balls to spare.
In a breathtaking finish, the victory arrived with a slog-swept six over midwicket from the first ball of the final over, Theron's eyes having lit up when Cameron White handed the ball to David Hussey. But White had bowled out all his frontline men in the search for those last few wickets, and his choice was down to Hussey or the medium pace of the debutant Mitchell Marsh.
Cummins had delivered a double-wicket maiden that left South Africa in major trouble at 18 for 3. Colin Ingram played on when he tried to drive a wider ball from Cummis and then JP Duminy, who failed to score, edged a pearler to slip, where Hussey flew to his right to take an equally impressive catch.
Earlier, Teenage debutant Mitchell Marsh hit four sixes in the last two overs to give Australia's innings a late boost.
Australia made 147 for eight in their 20 overs. Marsh hit 36 off 21 balls as the last two overs yielded 35 runs, breaking the shackles imposed by South Africa's bowlers for most of the innings.
Marsh, 19, was handed his first cap, joining brother Shaun and father Geoff as Australian international cricketers, because fellow all-rounder Shane Watson was ruled out by what was described as a minor hip injury.
Marsh joined skipper Cameron White when Australia were struggling at 87 for five with one ball remaining in the 14th over. He played a supporting role as White batted aggressively before being run out for 39 off 26 balls in the 17th over, then showed his potential as one of Australia's most promising young players.
His first six was off Wayne Parnell in an over which brought 15 runs, then he thrashed three more sixes off Morne Morkel before he was bowled off the last ball of the innings.
With Australia having won the first match by five wickets in Cape Town on Thursday, South Africa's bowlers dominated the early part of the innings, with Lonwabo Tsotsobe producing his country's most economical four-over spell by taking two for 11, including a first spell of one for six.
Morkel and Rusty Theron also took two wickets each on a pitch which looked ideal for batting but which had some uneven bounce.
Australia 147 for 8 (White 39, M Marsh 36, Tsotsobe 2-11, Theron 2-28, Morkel 2-37)
South Africa 148 for 7 (Botha 34, Theron 31*, Pattinson 2-17, Cummins 2-26)
Result South Africa beat Australia by 3 wickets
MOM Juan Theron (South Africa)