Klaas above: Aussies swept 3-0 by South Africa

An emotional maiden century from Marnus Labuschagne in the country of his birth wasn't enough to save Australia from a fifth consecutive ODI defeat and a 3-0 thumping at the hands of an undermanned South African side in Potchefstroom.

Labuschagne's first ODI hundred, scored just a 45-minute drive away from where he was born and with 50 delighted family members and friends in the stands, was the only high point of another disappointing day for the tourists, who have now won just one of their past 12 one-day games against the Proteas.

In a carnival-like atmosphere at Senwes Park in the student town known colloquially as 'Potch', Labuschagne's run-a-ball 108 steered Australia to 7-254 after Proteas skipper Quinton de Kock had won a crucial toss and elected to bowl first in the knowledge that 12 of the 18 previous ODIs at this venue had been won by the team batting second.

No other Australian batsman scored more than 36 and the target proved well within reach of the young South African batting line-up, who cruised home with the loss of just four wickets.

It's the second time in three-and-a-half years that Australia have suffered a one-day series whitewash in South Africa, having been thrashed 5-0 here in 2016 when they rested their star fast bowlers ahead of the home summer.

But given the Aussies have been at full strength for most of this series, and they faced a Proteas side here that was minus first-choice players Kagiso Rabada, Faf du Plessis, Lungi Ngidi, Tabraiz Shamsi and Rassie van der Dussen, another winless campaign will give coach Justin Langer plenty to ponder ahead of next week's series against New Zealand, starting in Sydney on Friday.

However, with the next World Cup still three years away, the match will be best remembered for Labuschagne's hundred, a breakthrough knock in just his sixth ODI that continued his remarkable summer of run-scoring.

Labuschagne took a risky second run when he was on 98, diving full length to make his ground just before the stumps were broken, then unleashed a powerful roar and acknowledged the Australian dressing-room and his family and friends in the western stand.

But Labuschagne's moment was the only piece of joy for the Australian batsmen, with only a late flurry from the Queenslander and recalled quick Jhye Richardson (24 not out from 20 balls) steering them to somewhere near a respectable score.

Emboldened by the absence of his tormentor Mitchell Starc, who has returned home to watch wife Alyssa Healy play in Sunday's T20 World Cup final at the MCG, de Kock gave the Proteas a strong start in the run chase, including an audacious ramp shot off the bowling of Kane Richardson that sailed into the crowd on the northern bank.

But despite Starc's dominance of de Kock on this tour, it is Josh Hazlewood who has dismissed the left-hander more times than any other bowler in international cricket and he got him again here, finding an inside edge back onto the stumps to make it 10 dismissals in all formats and six times in 12 one-day games.

But as had been the case in the opening two matches of the series, South Africa's lesser-known batsmen stepped up, with JJ Smuts (a career-best 84 from 98 balls), Heinrich Klaasen (68no from 63) and Kyle Verreynne (50 from 50) steering the hosts to victory with 27 balls to spare.

Having scored just one half-century in 14 ODIs before this series, Klaasen has produced scores of 123no, 51 and 68no for a total of 242 runs, breaking Carl Hooper's 21-year-old record for the most by a No.5 batsman in a three-match ODI series.

Hazlewood (2-37) and Adam Zampa (1-45) performed admirably with the ball, but the two Richardsons copped some punishment in their first games of the series, finishing with combined figures of 1-121 from 19 overs.

The Proteas onslaught delighted the vocal sold-out crowd of mostly students from the local university, who hauled eskies, deck chairs and even mini BBQs into the ground and enjoyed the smell and smoke from the traditional Afrikaner braais that wafted across the playing arena throughout the match.

A series win for Australia on the T20 leg of this tour and the reverse scoreline in the ODIs means they will take away sweet and sour memories of this campaign ahead of their matches against the Black Caps later this month that will bring the elongated international summer of cricket to a close.

Australia's Qantas Tour of South Africa 2020

Australia T20 squad: Aaron Finch (c), Sean Abbott, Ashton Agar, Alex Carey, Pat Cummins, Mitch Marsh, Jhye Richardson, Kane Richardson, D'Arcy Short, Steve Smith, Mitchell Starc, Matthew Wade, David Warner, Adam Zampa

Australia ODI squad: Aaron Finch (c), Ashton Agar, Alex Carey (vc), Pat Cummins (vc), Josh Hazlewood, Marnus Labuschagne, Mitch Marsh, Jhye Richardson, Kane Richardson, D'Arcy Short, Steve Smith, Mitchell Starc, Matthew Wade, David Warner, Adam Zampa

First T20: Australia won by 107 runs

Second T20: South Africa won by 12 runs

Third T20: Australia won by 97 runs

First ODI: South Africa won by 74 runs

Second ODI: South Africa won by six wickets

Third ODI: South Africa won by six wickets