Ben Stokes' muscular late attack ensured the opening day of the second Test against South Africa belonged to England as they reached stumps at 317 for five.
England's batsmen controlled for the majority of the day but had threatened to waste excellent conditions to post a big first-innings total after the top-order failed to cash in on starts.
Alex Hales passed fifty for the first time in Tests while Joe Root gracefully reached the same mark, but when the Yorkshireman fell soon after, the match was evenly poised.
Stokes ensured that any parity did not last for long as he took the game by the scruff of the neck, most significantly after the second new ball was taken.
The Durham all-rounder immediately crashed four boundaries in the first over with it, as he targeted debutant Chris Morris, and more was to come as he and Jonny Bairstow did not let up.
Together they hit 46 in the seven overs with the new ball to balloon their unbroken stand to 94 runs from 115 balls.
All-rounder Ben Stokes took up the attack late on the opening day to ensure England fully profited on good conditions for batting
Stokes reached the close unbeaten on 74, with Bairstow on 39, and will start tomorrow looking to make the significant contributions requested by Head Coach Trevor Bayliss before the match.
Bayliss had few gripes after the emphatic Durban success, however, he did point to the need for his top-order batsmen to convert starts into hundreds.
Five of the top-six got starts in today, and England were at one stage 167 for two, but those solid foundations were rocked when Kagiso Rabada struck twice in as many balls around tea.
Nick Compton made 45 before he pulled the 20-year-old seamer to midwicket to prompt the interval and, from the first ball after the break, James Taylor edged to recalled wicketkeeper Quinton de Kock.
That brought Stokes to the crease and, after negotiating the hat-trick ball, lost Root moments after posting another half-century.
Where others might have feared the world's top-ranked nation were making their move the Durham all-rounder counter-punched.
Stokes' innings was highlighted by eye-catching on-drives but it was his assertiveness when the second new-ball arrived that most most impressive as he cleverly waited for his moment to strike.
Stokes had been 42 when Proteas skipper Hashim Amla took the second new ball and, after he opted not to throw it to his most experience seamer Morne Morkel, Stokes went full throttle at inexperienced pair Morris and Rabada, brought in to the team in place of injured pair Dale Steyn and Kyle Abbott.
Opener Alex Hales scored his first Test fifty after also ending England's eight-game wait for a half-century opening stand
The runs flowed, Morris' first over cost 17 as Stokes raced to his fifty, and with Bairstow dovetailing at the other end the hosts ended the day protecting the boundaries rather than trying to claw their way into the England tail.
Cook was the only batsman to fall in the morning session after he won the toss and elected to bat in picture-perfect conditions.
With Hales the skipper registered England's first half-century stand for eight Tests and it took a superb diving catch from Morris, diving low to his left at third slip, off Rabada to dismiss Cook for 27.
Hales had been similarly untroubled as he reached his maiden fifty until he got a brute of a ball from Morkel and AB de Villiers dived across first slip to hold his 200th Test dismissal.
Root survived a dropped chance on 13, when Morris spilled a tough chance in the gully, before Rabada squared him up with a short ball that flew into the air but out of reach as De Villiers raced in from slip.
The Yorkshireman was rarely troubled thereafter and with Compton, England appeared set to go to tea in full control with only two wickets down.
Rabada's quick strikes put paid to that and when Root then momentarily lost his concentration a couple of balls after getting to his half-century, England were 223 for five and showing signs of letting their good early work slip.
If Stokes sensed the danger he never revealed it as he hit the ball crisply without taking risk before unleashing his full brute force of strokeplay on the second new ball.