Zak Crawley's maiden Test half-century gave England a solid foundation before South Africa struck back on the first day of the fourth and final Test at the Wanderers Stadium on Friday.
Holding an unbeatable 2-1 series lead, England were 192 for four when bad light ended a rain-shortened day.England's youthful opening pair of Crawley (66) and Dom Sibley (39) shared their team's first century opening partnership since 2016 and blunted South Africa's fast bowlers on a pitch which both captains expected to be challenging for batsmen.
However, there could be trouble ahead for star all-rounder Ben Stokes who became embroiled in an angry exchange with a spectator as he left the field following his dismissal for just two.
He could face disciplinary action for uttering an audible obscenity, which is a level one offence according to the International Cricket Council's code of conduct.
Meanwhile, Crawley said he was working hard on the mental aspects of his game.
"It's nice to get us off to a good start and we're in a really good position," said the opener.
"The people who think the best are usually the best players."Crawley, 21, and Sibley, 24, put on 107 before Sibley was caught down the leg side by wicketkeeper Quinton de Kock to give new cap Beuran Hendricks his first Test wicket.
South Africa claimed three more wickets to have England at a slightly precarious 157 for four but captain Joe Root and Ollie Pope took the tourists safely through to the close in deteriorating light.
Rain prevented any play before lunch and the South African bowling was surprisingly unthreatening when it did get underway.
Both teams opted for an all-seam attack on a pitch which usually favours fast bowlers but there was no discernible swing or sharp movement off the surface as England's openers scored at better than three runs an over.
"It's one of those pitches where everyone talks about the pace of it but it was fine today. It was a nice place to bat," said Crawley.
'Bit more aggression'
"After tea it got harder so I think if we get 300 it will be a very good score."
England were 100 for no wicket at tea but South Africa changed their tactics after the interval, bowling more short-pitched deliveries.
"I thought they were very comfortable with the new ball with us pitching it up," said Hendricks.
"We chatted at drinks and at tea to make sure they don't feel comfortable."
He said a plan to bowl more short balls and make the batsmen less assured with their footwork had worked.
"A bit more aggression came out," he said.
The left-armed Hendricks, who plays most of his domestic cricket at the Wanderers, said he expected the pitch would quicken up as the match went on.
Crawley, in his fourth Test, batted confidently from the start and drove strongly off the front foot, although on 56, shortly before tea, he was hit on the helmet when he missed a pull against Anrich Nortje.
He made his runs off 112 balls and hit 11 fours before he provided Rassie van der Dussen with one of three catches at first slip, edging a ball from Vernon Philander which bounced more than usual.
Joe Denly was dropped twice before he was caught by Van der Dussen off Dane Paterson for 27 and Stokes made only two before he played an extravagant drive against Anrich Nortje to give Van der Dussen his third catch.