England tightened their grip on the third day of the first Test at Kingsmead on Monday against a South African team weakened by an injury to fast bowler Dale Steyn.
England built on a first innings lead of 89, reaching 58 for two in their second innings at tea, an overall lead of 147.
Dean Elgar carried his bat for a fighting 118 not out but had minimal support from his teammates as South Africa were bowled out for 214. Stuart Broad and Moeen Ali took four wickets each for England.
South Africa suffered a blow early in the second innings when Steyn left the field with a right shoulder strain after bowling two balls of his fourth over.
He returned soon afterwards and bowled three balls of the 21st over, almost forcing Nick Compton to play on to his stumps, before crying off again. It was announced that he would go for a scan later.
Steyn, who missed most of a recent series in India with a groin injury, took four for 70 in the first innings in his first match appearance since November 5.
Off-spinner Dane Piedt took the first two wickets in the second innings, trapping England captain Alastair Cook leg before wicket for seven before having Alex Hales caught at long-on for 26.
England could have been three down if Elgar, South Africa's batting hero, had held a chance from Compton, on 11, at second slip off Morne Morkel.
In Morkel's next over, Joe Root, on six, gloved an attempted hook and wicketkeeper AB de Villiers leapt high but could not hold a difficult chance.
The left-handed Elgar batted resolutely for more than six hours while his teammates struggled, reaching his fourth Test century off 211 balls, with eight fours and a six.
He did not add to his boundary count before running out of partners after facing 246 deliveries.
Elgar was the sixth South African to bat unbeaten through a Test innings.
Fellow left-hander Gary Kirsten was the most recent to perform the feat before Elgar, making 100 not out in a total of 239 against Pakistan in Faisalabad in 1997/98.
Broad followed up his three wickets on the second day with an early breakthrough on Monday, bowling Temba Bavuma off an inside edge with the second ball of the morning, without addition to the overnight total of 137 for four. Broad had figures of four for 25.
Ali took two wickets in successive overs, dismissing JP Duminy and Kyle Abbott, as South Africa crashed to 156 for seven before Steyn helped Elgar add 54 for the eighth wicket.
Ali ended the partnership shortly before the second new ball was due when Steyn lofted a catch to mid-off. He took four for 69.
Steven Finn wrapped up the innings, taking the last two wickets in the space of four balls in the second over with the new ball.
