The beleaguered Proteas are joint bottom of the table with Afghanistan and know a defeat at Southampton will probably end their hopes of reaching the semi-finals.
The West Indies, meanwhile, will be looking to bounce back from their battling loss to Australia last time out and produce the kind of devastating bowling that saw Pakistan skittled for 105 in their opening match.
Victory for the Windies would also see them move level on four points with India, who continued their 100 per cent start to the tournament on Sunday with an impressive 36-run over previously undefeated Australia.
Here we look ahead to day 12 of the World Cup as well as back at day 11.
Hardik Pandya's short-arm jab for a straight six off Pat Cummins as India piled up 352 for five represented perhaps the ideal mixture of classic straight batting and modern big hitting. India entered the tournament insisting there is still time to measure your batting but also post totals to defend. And so it proved again at The Oval as they overwhelmed the Australians.
Bhuvneshwar Kumar's rasping ball dislodged Marcus Stoinis' off stump, and that after brushing the all-rounder's back pad. Kumar and Jasprit Bumrah again proved too wily to dominate as Australia were bowled out for 316 in reply.
Player to watch
West Indies all-rounder Andre Russell has the ability to win a match with bat or ball but looks to have been affected by his long-standing knee injury during the World Cup so far. However, Windies assistant coach Roddy Estwick assures Russell will be fine to face South Africa, saying: "Andre is a warrior, he is a soldier. He's a strong man mentally and he will be up for the game."
Quote of the day
It has not been smooth sailing on or off the pitch for injury-hit South Africa but they know any more defeats could spell the end of their World Cup hopes.
Tweet of day 11
Former Pakistan pace ace Shoaib Akhtar was not shy in criticising the controversial 'zing' bails, admitting the frequency with which they do not fall has him as confused as everyone else.
World Cup snapshot
What's up next?
June 11: Bangladesh v Sri Lanka at Bristol.