Sri Lanka still find themselves in with a chance to make it into the semi-finals after their remarkable win over hosts England at Headingley.
The qualification race has heated up as four teams vie to stay in the competition and claim the final spot in the top four.
A win for Sri Lanka will help them see make gains in the points table although any such progress amidst the current backdrop means this could be a momentary shift of momentum.
However, Sri Lanka's inconsistencies have routinely caught up with them throughout this tournament as middle order collapses and lack of bowling depth has been constantly the concern for them in the World Cup.
Meanwhile, South Africa arrive into the contest with nothing to lose and only pride to fight for.
In the face of severe backlash from fans back home, senior player JP Duminy apologized for their embarrassing campaign.
"It's been pretty dismal from our part," said Duminy, who will take retirement from ODIs at the end of the tournament.
"We obviously want to apologise to the public and the South African fans for letting them down."
Despite the Proteas being under the cosh and troubled with all sorts of difficulties, Sri Lanka coach Chandika Hathurusingha warned his team of a spirited performance from their opponents.
"When you have no pressure of qualifying, they can come and play without any pressure, fearless cricket and that can get them going, so at the same time they can turn up and just want to go home, so you never know," he said.
Sri Lanka's veteran players had been receiving a lot of criticism from former cricketers with Angelo Mathews taking most of the blame for not being able to bind together the weak batting line-up.
Low scores tormented his confidence coming into the tournament but he managed to recover some of his lost crisp touch during the game against England.
Although still not at his fluent best, Mathews shouldered the responsibility and batted till the end of the innings to afford Sri Lanka respectability in the total they achieved.
The Proteas were on top of their game the last time these two teams met each other in a bilateral series.
South Africa dominated the Sri Lankans when they visited the rainbow nation just three months back, as the hosts handed out a brutal 5-0 thrashing in the ODI series.
Du Plessis and his men will hark back to a not so distant past to exploit the numerous inefficiencies visible in the Sri Lankan line-up.
Sri Lanka: Dimuth Karunaratne (c), Avishka Fernando, Suranga Lakmal, Lasith Malinga, Angelo Mathews, Jeevan Mendis, Kusal Mendis, Kusal Perera (wk), Thisara Perera, Nuwan Pradeep, Dhananjaya de Silva, Milinda Siriwardana, Lahiru Thirimanne, Isuru Udana, Jeffrey Vandersay
South Africa: Faf du Plessis (c), Aiden Markram, Quinton de Kock (wk), Hashim Amla, Rassie van der Dussen, David Miller, Chris Morris, Andile Phehlukwayo, JP Duminy, Dwaine Pretorius, Beuran Hendricks, Kagiso Rabada, Lungi Ngidi, Imran Tahir, Tabraiz Shamsi