South Africa made England pay for dropped catches as they eyed a potentially series-clinching lead on the fourth day of the third Test at Lord's on Sunday.
The Proteas were 216 for four in their second innings, 210 runs ahead, when bad light and rain forced an early lunch.
Hashim Amla was 94 not out and AB de Villiers 24 not out in a stand so far worth 52 after both batsmen had been dropped on single figure scores. (Day 4 full report)
South Africa are 1-0 up in the three-match series after an innings win in the first Test at The Oval, where Amla made a national record 311 not out.
They only have to avoid defeat at Lord's to replace England as the world's top-ranked Test side.
The Proteas resumed Sunday on 145 for three, with Amla 57 not out and nightwatchman Dale Steyn unbeaten on nought.
Fast bowler Steyn, having bounced England's tail, got plenty of short stuff in return.
But having added 33 with Amla and hung around for more than an hour, Steyn fended at a rising delivery from paceman Stuart Broad and James Taylor took the simple catch at short leg to leave South Africa 164 for four.
De Villiers got off the mark first ball by pulling Broad to fine leg and followed that up with another four, exemplary footwork taking him down the pitch to loft off-spinner Graeme Swann over midicket.
However, he was still on eight when he mistimed a drive off Swann only for James Anderson, at short midwicket, to drop the straightforward chance.
Amla, dropped on two Saturday when he glanced Broad down the legside and diving wicket-keeper Matt Prior just failed to cling on to the difficult left-handed catch, was content to bide his time Sunday.
He didn't score a boundary in the morning session but still moved to within sight of a hundred.