Chasing a target of 292 runs, Australia got off to a bad start as seamer Lungi Ngidi removed both the openers, Aaron Finch (10) and David Warner (25), in the fifth and ninth over respectively. Steve Smith and Marnus Labuschagne then staged a recovery for the Aussies and took charge of the chase and played cautiously. In the 27th over, bowled by Keshav Maharaj, Smith completed his half-century but in the same over Labuschagne (41) was dismissed.
Mitchell Marsh then came out to bat but failed to leave a mark on the field as he only managed to score 16 runs before Ngidi got hold of him in the 34th over. In the next over, South Africa got the much anticipated wicket of Smith (76), who was given LBW off Anrich Nortje's ball.
The hosts then did not allow Australia to form a good partnership and the visitors kept on losing wickets. Australia were all out on 217 runs in the 46 over.Earlier, after deciding to bat first, South Africa witnessed a very poor start as Janneman Malan was given LBW off the very first delivery of the innings, bowled by Mitchell Starc.
Quinton de Kock was then joined by Temba Bavuma out on the field but their partnership also did not last as the former was dismissed by Josh Hazlewood. Soon after, Bavuma (26) was sent back to the pavilion by Pat Cummins as he bowled the batsman.
Klaasen and Kyle Verreynne then came out to bat and provided their side with some momentum as they formed a 78-run partnership. Kyle Verreynne was just two runs short from completing half-century when Cummins dismissed him.
David Miller was the next batsman and played brilliantly along with Klaasen, who went on to score his maiden ODI century. Miller, who played a knock of 64 runs, was caught behind off Cummins' delivery in the 49th over.
In the same over, Andile Phehlukwayo was run out on a duck. Klaasen's unbeaten knock of 123 runs helped South Africa post a respectable target of 292 runs for Australia. The second ODI will be played on March 4.