A record-breaking partnership between South African centurions Faf du Plessis and David Miller has set up a 40-run win over Australia in Hobart, clinching the one-day international series.
The Proteas' mammoth 5-320 proved out of reach for Australia on Sunday night despite a determined 106 from veteran Shaun Marsh.
Marsh restored the Australian innings in a century stand with allrounder Marcus Stoinis (63) after Australia were left wobbling at 3-39 in the 11th over.
But when he fell in the 42nd over, his side's chances slid with him.
Alex Carey (42) and Glenn Maxwell (35) tried to launch the required late blows but didn't connect often enough as Australia finished on 9-280.
"It's always nice to score a hundred for your country. Disappointing that we couldn't get over the line at the end," Marsh said.
Dale Steyn finished with 3-45, while Kagiso Rabada also picked up three wickets.
After being sent in, du Plessis (125) and Miller (139) put on a 252-run stand - the biggest ODI partnership against Australia.
The pair came together at 3-55 and steadied the South African innings before feasting late on Australia's seamers.
They weren't without their luck, though, in a partnership that bettered Marvin Atapattu and Sanath Jayasuriya's 237-run stand 15 years ago for Sri Lanka in Sydney.
Carey dropped du Plessis on 29 off Maxwell in what should have been a regulation caught behind.
Maxwell had a second moment of frustration in the 33rd over when he appeared to have trapped Miller in front for 41.
But a review, called for at the last moment by the batsmen, showed the ball narrowly travelling over the stumps.
"It was one of those where you just hold your breath and hope for the best," Millar said, adding Faf made the signal to refer but the umpire didn't hear or see him.
"He (the umpire) said it's too late. Then I said no, well, Faf's already shown it like that. Then obviously it went upstairs."
Mitchell Starc finished with 2-57, while Stoinis nabbed two wickets but conceded 70 off seven overs.
South Africa smashed 130 off the final 10 overs, including 75 off the last five.
"It was tough in the beginning. We absorbed the good bowling and waited for an opportunity," du Plessis said.
"And then we were just trying to have a bit of fun."
Australia's chase started disastrously, losing Chris Lynn to a first-ball duck before Aaron Finch (11) and Travis Head (six) joined him.
South Africa take the series 2-1 in front of 5231 fans after Australia had levelled in Adelaide with a seven-run win in game two.