The South African cricketers are 46 for two in reply to West Indies's modest total of 231 at the end of the first day's play in the third and final Test in Barbados.
Captain Graeme Smith is unbeaten on 35 at the close, with nightwatchman Paul Harris two not out for the visitors who are 1-0 up in the series.
Alviro Petersen made one and Hashim Amla five.
Earlier, off-spinner Johan Botha was the chief destroyer with four for 56 as West Indies were bowled out in 73.5 overs.
Dwayne Bravo top-scored with 61 and Narsingh Deonarine made 46.
Fast bowler Dale Steyn picked up three for 37 including the prize wicket of Chris Gayle for 20 when the skipper played the ball on to his stumps.
West Indies suffered a pre-match setback when Nelon Pascal pulled out with a neck problem and paceman Brandon Bess was called in for a shock debut.