Bridgetown: South Africa were 46-2 at stumps on the first day of the final Test against West Indies on Saturday after their attack, led by Johan Botha and Dale Steyn, had helped restrict the home team to 231 all out.
Off-spinner Botha was the most successful Proteas bowler with four wickets for 56 runs from 19.5 overs, as West Indies, electing to bat on a hard, true pitch at Kensington Oval, were dismissed about 40 minutes before the scheduled close.
Steyn supported with three for 37 from 13 overs, and Jacques Kallis took two for 36 from 12.
Dwayne Bravo struck four fours and one six in the top score of 61 from 104 balls for West Indies, with left-hander Narsingh Deonarine being the only other batsman to offer prolonged resistance, making 46.
South Africa then suffered an early setback, when opener Alviro Petersen was caught at mid-wicket off Kemar Roach for one, miscuing a hook at a short ball.
And Hashim Amla, the most prolific batsmen in the preceding limited-overs matches, continued to struggle in the longer format, when he was caught at backward point for five, cutting Sulieman Benn's first delivery just before the close.
Earlier, Deonarine and Shivnarine Chanderpaul thwarted South Africa, after they made a bright start before lunch.
The South African new-ball pair of Morkel and Steyn removed West Indies openers Dale Richards and Chris Gayle cheaply.
Morkel made the breakthrough, when he trapped Richards lbw for a duck, and Steyn then bowled West Indies captain Gayle for 20 to leave the hosts 21 for two.
But the Proteas were made to toil for the remainder of the session, as Deonarine and Chanderpaul batted through to the interval with little or no alarms.
After lunch, Botha took all three West Indies wickets to fall to tighten South Africa's grip, as West Indies slumped to 159 for five at tea.
Botha struck in the first over after lunch, when Chanderpaul, a century-maker in the previous Test, was caught at slip for 22 to end a 55-run stand for the third wicket with Deonarine.
Botha then had Brendan Nash, another left-hander and another century-maker in the previous Test, lbw for two playing back and across, after TV umpire Asad Rauf overturned umpire Simon Taufel's not-out verdict, following a referral from the Proteas.
With Botha bowling steadily at one end, and Morkel steaming-in at the other end, run scoring dried-up for West Indies, and the pressure took a toll on Deonarine.
Botha bowled Deonarine, when the batsman pulled at a delivery that wasn't quite that short.
Denesh Ramdin joined Dwayne Bravo, and for the next hour-and-a-quarter, they consolidated West Indies' position.
After tea, Kallis had Ramdin caught at deep fine leg for 27 hooking to end his stand of 76 with Bravo, whose 50 came from 88 balls with two off Steyn to mid-on.
The South Africans then ran through the tail-end of the West Indies batting, snaring the last five wickets for 50 runs from 79 deliveries.
South Africa lead the three-Test series 1-0, after they won the first Test by 163 runs inside four days last Sunday at Queen's Park Oval in Trinidad, and the second Test was drawn at Warner Park in St. Kitts.
West Indies 231 (Bravo 61, Botha 4-56, Steyn 3-37)
South Africa 46 for 2 (Smith 35*)
Result South Africa trail by 185 runs