Rabada's seven-wicket best keeps SA on victory track
South Africa 475 and 42 for 1 (Cook 23*, Amla 16*) lead England 342 (Cook 76, Root 76, Rabada 7-112) by 175 runs
Scorecard and ball-by-ball details
Four specialist bowlers and one of them succumbing to injury. For Kagiso Rabada, an up-and-coming fast bowler acting as spearhead one moment, workhorse the next, it was an onerous burden. But Rabada was up to the task, producing the most redoubtable display of his fledgling career to leave South Africa anticipating victory in the final Test in Centurion.
Radaba's return of 7 for 112, his finest figures in a Test career only five matches old, presented South Africa with a first-innings lead of 133 which they extended to 175 for the loss of Dean Elgar by the time bad light fell upon the third day.
With reason to expect that this surly surface will become more indifferent as the Test progresses, South Africa retain strong hopes of a consolation victory which would reduce the series margin to 2-1 and enable them to claim their first victory in 10 Tests.
Rabada tore through England's batting line-up with three quick wickets on the stroke of lunch, removing Joe Root, James Taylor and Jonny Bairstow in succession to turn the Test heavily in South Africa's favour. With Kyle Abbott leaving the field as tea approached for intensive treatment on a tight hamstring, South Africa's four-strong attack was under heavy strain and Rabada, at the tender age of 20, bore most of it.
By the time he led South Africa from the field half an hour after tea, his figures were the third best ever recorded at Centurion, outdone only by two other outstanding displays of recent vintage - Abbott's 7 for 29 against Pakistan in 2013 and Mitchell Johnson's terrorising of South Africa to claim 7 for 65 a year later.
The accolades were thoroughly deserved for a display of great control, nous and stamina. His best Test figures followed a return of 5 for 78 in the third Test in Johannesburg. His achievements so young are rarely achieved. An unrewarding Test introduction on spin-friendly surfaces in India has been well and truly put behind him.
His progress this series has been swift, his speeds around 145kph until fatigue took a hold and he sensibly throttled back, and his control of line excellent. He caresses the pitch - the antithesis of Hardus Viljoen who in Johannesburg tried to deep mine it. At 20 years old, he is a prize asset but he is still physically developing and South Africa will have to nurture him with care as they prepare for a future - not too distant now - without Dale Steyn.
Alastair Cook, the first wicket to fall on the third day, must wait for the potential accolade of the youngest player to reach 10,000 Test runs - and as he watches England flounder after losing an influential toss he must be ageing by the minute.
Cook, 67 not out overnight, began fifty runs short of the record, but he added only nine runs in an hour before he was unpicked by Morne Morkel, an excellent delivery from around the wicket which bounced and seamed away to take the edge. The wicket stirred Morkel, whose signal has come and gone like a mobile in an iffy reception area.
Cook has one more innings in South Africa to secure a record that looks inevitable, barring injury, as he still has a full English summer to achieve it. He has ticked off the record thousand by thousand since his Test career began to evolve, the youngest batsman at every measuring point.
The removal of Root, the mainstay of England's batting line-up, was a huge breakthrough for South Africa. Root had launched England's challenge by taking three back-foot boundaries off him in an over, the first of them thick-edged wide of gully, but he became the first victim of the morning when Rabada produced one that shaped away a tad around off stump for Quinton de Kock to hold a simple catch.
Rabada struck again when Taylor was too early on a pull shot that was both too wide and high for the shot, especially with wickets falling and lunch approaching, and cue ended the ball to the wicketkeeper. Taylor might have been defeated by the inconsistent bounce, but it was an unwise shot with a short leg and two men back for the shot.
Three balls later - the last before the interval - Rabada added Bairstow for nought. It was a dismissal that emphasised he is already a bowler of craft, an offcutter bouncing back at Bairstow who failed to withdraw from the shot to catch the glove and give de Kock his fourth catch of the innings.
South Africa had squandered two reviews in the morning session. Morkel's belief that he can get Cook caught down the leg side is all very well, but not when South Africa review an appeal - as they did when Cook was 70 - that missed the bat by several inches. The noise must have been that made when a theory collides with reality.
There was over-eagerness, too, in de Kock's belief that he had held a leg-side tickle from Root off the offspinner, Dane Piedt. Such considerations were soon forgotten as Rabada made deep inroads into England's order, reducing them to 211 for 6 - still 63 short of avoiding the follow-on.
Rabada added the wicket of Ben Stokes, picked off at second slip with only the second delivery with the second new ball, a success Rabada greeted with nothing more aggressive than the gentlest of smiles.
England would have sensed an unlikely escape route, especially with Moeen Ali fashioning resistance with his usual languid unpredictability, leaving South Africa eminently grateful for the charitable departure of Chris Woakes shortly before tea.
JP Duminy, a notional fifth bowler, whose confidence impaired by an injury in India when he split the webbing of his bowling hand, looks in bad shape, bowling wise, and seems to have adopted a strange, whirly Harbhajan Singh impression.
He did nothing more than slip a straight one across Woakes, who edged it into the pads of the wicketkeeper Quinton de Kock and from there to first slip where Dean Elgar held a simple chance. Woakes had also been dropped on 1 when de Kock failed to hold a one-handed catch above his head off Morkel.
After tea, South Africa threw the ball to Rabada once more. By the time he added his seventh - Stuart Broad obligingly pulling to deep square leg - he was running on empty, about 10kph down on his speed at the start of the Test, unable to summon the energy to run and congratulate the fielder.
Moeen's departure to Morkel, for 61, driving on the up to extra cover, finally gave Rabada release. His 29 overs had revealed a few home truths about the arduous nature of Test cricket. In another 24 hours or so, perhaps even less, he would be doing it all again.
David Hopps is a general editor at ESPNcricinfo @davidkhopps