A partnership of 127 for the second wicket between Hashim Amla and Faf du Plessis, the second highest ever for the wicket for South Africa at a World Cup, laid the platform and then captain AB de Villiers and Rilee Rossouw took advantage and bolstered South Africa’s knock.
At the end of 40 overs South Africa were 258/3.
The pair of Rossouw and De Villiers have added 112 with both moving to half centuries in the process.
One gets the feeling that the pair will now look to kick on as South Africa go in search of a score in the region of 330-plus.
There were nervous moments at the beginning of South Africa’s innings after opting to bat first as Quinton de Kock departed cheaply but Amla, who managed 65 off 88 balls, and Du Plessis, who scored a second consecutive half-ton, salvaged things and batted the Proteas into a good position.
The West Indies mangled to get a breakthrough thanks to Chris Gayle in the 30th over as he struck twice in three balls to dismiss Du Pleases, well caught behind by Denesh Ramdin, and then trapped Amla leg-before.
But De Villiers and Rossouw settled in quickly and have now swung the game firmly in favour of South Africa with 10 overs left in their innings.