Captain Graeme Smith defended South Africa's ponderous approach and said a lead of 100 could be enough for victory over West Indies in the second Test. Smith took almost eight hours over his 148, and the batsmen who followed took 62 overs to make 103 on day three.
"It's very difficult to score quickly on this wicket," Smith said.
"The best time to try and score runs is also the most dangerous time, and that's with the new ball. The West Indies were also very defensive."
The tourists took a lead of 23 into day four in Trinidad, with Ashwell Prince, who was 41 not out, and Mark Boucher, unbeaten on 28, sharing a stand of 67.
Smith added: "It's important that we take a decent lead.
"It's the first time we are putting the West Indies under pressure in the series and a lead of anything over 100 will be very valuable."
"It's great to make runs in tough conditions, and to be able to put the team in a good position."