Opening batsman Ashwell Prince failed for the second time in the match as South Africa set out to build on a slender first innings lead on the third day of the third Test against England at Newlands on Tuesday.
South Africa were 56 for one at lunch, an overall lead of 74.
Prince, out for nought in the first innings, made 15 before he was leg before wicket to off-spinner Graeme Swann's seventh ball of the innings.
England were all out for 273 in their first innings earlier, losing their last three wickets for 32 runs in six overs. It gave South Africa a lead of 18 runs.
Fast bowler Morne Morkel took wickets off successive balls in the first over of the day to complete his second five-wicket haul in Tests. He finished with five for 75.
Morkel had the right-handed Swann and the left-handed James Anderson caught at first slip by South African captain Graeme Smith off fast lifting deliveries.
Matt Prior hit boldly to take his overnight score from 52 to 76 before he was bowled off a bottom edge when he shaped to pull Dale Steyn, who had figures of four for 74.
Prince survived one review, successfully winning the reversal of a leg side caught behind decision made by umpire Daryl Harper off the bowling of Anderson when he had five. A replay showed the ball had glanced off his pad with the bat not near the ball.
But there seemed little point to his second call for a review when he prodded forward to Swann and was given out by umpire Tony Hill. He looked palpably out and this was confirmed by a replay.