Graeme Smith marked his 100th Test with his 25th century as he and Hashim Amla set up a roadblock to England progress on the third morning of the first Investec Test.
South Africa's second-wicket pair reprised what they had witnessed themselves from Alastair Cook and Jonathan Trott at the Kia Oval two days ago. England's stone-wallers had added 170 in 58 overs after the loss of captain Andrew Strauss for a duck at the very start of this series.
Today, in reply to 385 and after Smith's opening partner Alviro Petersen had also made nought yesterday, South Africa moved from 86 for one to a lunchtime 187 on the back of an unbroken stand of 186.
Smith (103no) produced the slowest half-century of his 10-year career, from 160 balls, but stepped on the accelerator to reach three figures from only 41 more deliveries when he cut Tim Bresnan for his 16th four.
England tried to strangle his scoring rate by bowling outside off stump to the left-hander, so adept off his legs.
But Smith passed the patience test, and it was not until he was at last beyond his 50 that he began to milk runs off Graeme Swann - who conceded 21 runs from the last two overs of his early spell.
On a slow pitch, expected to eventually favour spin if the sun stays out, England then hatched a plan to bowl to Smith's strength a little more and post two midwicket catchers to Stuart Broad. But he took the calculated risk, and clipped two more boundaries to take his sudden surge of fours to six from 14 balls.
Amla (80no) was often more pleasing on the eye. He reached a 110-ball 50, with six fours, but reserved some of his best for his seventh and eighth boundaries - a memorable back-foot force past extra-cover off James Anderson and then a drive on the up in the same direction off Broad.
England surprisingly turned to Ravi Bopara, before Bresnan, and then switched Swann the pavilion end. But nothing Strauss did even hinted at a breakthrough.