"He is very much about tactical 'how am I going to get that batter out?' A lot of bowlers work technically on what they're doing but don't always focus enough on the other end". "To have that repsonsibility and then to back it up, it gives me more confidence", said Bess. "I'm sure he'll take a lot of confidence from the fact that he faced quite a few balls and got to spend some time in the middle". He stuck around for almost two-and-a-half hours, hitting six fours and one maximum for 36, but so much more was needed.
Sliced and diced by England's tricks, South Africa also found the tourist's spinners nearly unplayable, with Dom Bess keeping a tight line, but Root was rampant.
Root took three more wickets after the interval. Root accepted the chance to put the careworn hosts back in again, enforcing the follow-on for just the second time in his captaincy.
England - 1st innings: 499-9 decl.
South Africa had shown a hint of resistance on the third day through de Kock and Philander's half-century partnership. He had added 54 for the seventh wicket with Vernon Philander, 27 not out, when stumps were drawn.
With star all-rounder Stokes leading the charge once again, England built a commanding position in the match and had possibly carved out a key moment in the series, which is level at 1-1 but leaning heavily in the tourists' favor with one more Test to come.
South Africa was 15-0 in its second innings and had cut the deficit marginally to 275 when rain started and the players went off.
Yemen: Over 80 killed in missile attack, bloodiest since beginning of war
The victims were transported to a Marib city hospital, where a medical source earlier gave a toll of 83 dead and 148 injured. Yemeni President Abdrabbuh Mansour Hadi condemned the "cowardly" attack in a statement carried by Saba, a state news agency.
Bess took all his wickets in an unchanged 23-over spell from the northern, Duck Pond end, from late on Friday, when he took his first two wickets, until after lunch on Saturday.
As reported from day two, the Proteas' spearhead, who is supposedly out of sorts but leads the wicket-taking charts in the series with 14 - was adjudged to have run afoul of the ICC's limp-wristed regulations in his celebration of his cleaning up England captain Root with a pearler of a delivery.
Stokes was not brought into the attack until the 61st over.
Where Dom Bess' off-spin had been key earlier in the match, the quick men took the chance to assert themselves on proceedings in thrilling fashion as Stuart Broad, Sam Curran and Mark Wood all toppled the timbers.
Wood, too, geared up for his bowling return after 11 months out of the Test side by throwing the bat around to good effect, five times clearing the ropes - although he was the beneficiary of a weird episode on the way to 42 from 23 balls.
After Mark Wood struck twice, captain Faf du Plessis at least survived 123 balls for his 36. Rassie van der Dussen, who looked good for his 24 before chopping on as Bess found some turn from outside off, completed the set.