AB de Villiers and Ashwell Prince added 134 for the sixth wicket to put South Africa back in control on the second day of the third and final test at Bridgetown in Barbados.
South Africa will resume on 285 for six in reply to West Indies' 231 with Prince unbeaten on 55.
De Villiers curbed his natural attacking instincts with a patient 73 before he became Sulieman Benn's fourth victim.
He'd twice benefited from the West Indies' decision not to use the umpires' decision review system when he was caught behind trying to cut.
Benn finished with four for 49 from 31 overs of testing left-arm spin.
South Africa lead the series 1-0.