A fourth-wicket partnership of 68 runs put England in a promising position after an early struggle, going 43-3 after Root was dismissed for nine.
South Africa were reduced to 151 for five before lunch, with England’s James Anderson and Stuart Broad taking three wickets each.
After such low scores, the touring team, leading 1–0 in three Test series, knew they needed to deliver with the ball and found early breakthroughs when Alex Lees dismissed Lungi Ngidi to keeper Kyle Verynne.
Anrich Nortje’s pace was too high for Ollie Pope, who was clean bowled by a ball that went past the seam.
Kagiso Rabada claimed the prize money for Root, who was caught by Sarrell Ervee in the fourth attempt after groping the ball at first slip.
Out of form Crawley was under pressure but he played with focus and determination against both the pace and spin of Keshav Maharaj.
Bairstow was more confident and prepared to play his shots but for discussion of England’s new equestrian style, this was a reasonably conservative approach.
Rabada and Nortje put on 35 runs for the ninth wicket, the longest partnership of the innings, before South Africa were at 108 for eight.
In the morning session, England cheaply removed the tourists’ top order after South Africa captain Dean Elgar won the toss and elected to bat despite tough conditions after overnight rain.
Anderson, bowling at his home ground, saw early momentum from the seam and found the breakthrough when he found the inner edge of Erwee and took a brilliant catch by wicketkeeper Ben Foakes.
Anderson and Ollie Robinson were both hitting the outside edge regularly and Robinson thought he had claimed the skull of Elgar’s prize when Pope caught it at short mid-on on the bat-pad, but the umpire made a no-ball. indicated.
Broad was keen to work on an encouraging surface for the fast bowlers and he took full advantage of it.
After two lbw decisions were turned down, Broad dismissed Elgar for 12 with a full length delivery, which was in the hands of Bairstow at third slip.
Broad similarly dismissed Keegan Pietersen for 21 and Root took a catch at first slip to leave South Africa 41-3.
England captain Ben Stokes brought himself into the attack and struck his third ball – a loose short ball that Aiden Markram (14) attempted to pull off, but managed for only a simple high catch for grateful Fox.
Stokes struck again just before lunch, trapping Rassie van der Dussen (16) lbw and, although the video review supported the umpire’s call, the South African, who had advanced well, felt that He was unlucky with a tough decision.
It gave England a long evening session to bat on and after their poor start, they missed out on a crucial lead on Friday.