Ashwell Prince struck his second hundred of the npower series as South Africa took a firm grip on the Test match at Headingley.
Left-hander Prince, 31, followed his 101 in the draw at Lord's last week with another three-figure contribution, his ninth in 43 appearances at the top level.
He celebrated his latest landmark moments before tea, which the tourists took on 262 for four, a lead of 59 runs.
Prince ground out the Proteas' significant advantage during a century stand with AB de Villiers as England struggled for breakthroughs on the second day.
Only a maiden wicket for surprise debutant Darren Pattinson briefly interrupted South Africa's progress.
Once to a half-century, via the first of two straight sixes off left-arm spinner Monty Panesar, Prince continued his trend of converting starts - he has passed 50 on only 16 occasions. Apparently intent on preventing England's slow left-armer from settling - after a belated introduction in the 59th over - Prince went up the wicket for his first maximum to complete a 120-ball 50 which also contained seven fours.
He hit the next one from the crease, to wider long-on as the South Africans made good use of contrasting conditions to yesterday.
Their one loss came in the morning session when 29-year-old Pattinson won a fortuitous lbw decision against Hashim Amla.
There was little obvious help for England's four-strong seam attack, with minimal swing available to them and nothing notable in terms of sideways movement or unpredictable bounce.
But Pattinson deemed that irrelevant when he persuaded Daryl Harper to raise the finger after hitting Amla on the pads with a full toss angled down the leg-side, which appeared to be sliding wide of its intended target.
England, of course, thought they had Amla on nine last night - before controversy kicked in and Michael Vaughan's 'catch' at mid-off was scrubbed out.
Instead the number three stayed to share a 67-run stand with Prince, and there must have been some frustration among bowlers and fielders as Amla began to time the ball sweetly for boundaries square on either side of the wicket.
Vaughan had opened up with Andrew Flintoff and James Anderson this morning, and summoned Stuart Broad as his first change before allowing Pattinson his first opportunity - in the 38th over of the innings - to try again down the hill after his new-ball spell of 3-0-16-0 from the Kirkstall Lane end.
Prince pulled Pattinson's sixth ball of the morning, from the Kirkstall Lane end, for four.
Confronted with sunshine following early morning showers today, Amla then took his toll on Stuart Broad in particular.
He greeted Broad with a flash to the backward point boundary and then struck the same bowler for two fours in his next over, another cut followed by a handsome clip through midwicket.
Batting conditions were certainly an improvement on day one but although sunshine bathed the ground at the scheduled start time of 11am, the showers earlier this morning meant a 15-minute wait for England's attack.