With James Anderson ruled out of the first Test through injury, the responsibility of leading England's attack fell to Stuart Broad - and how he delivered on day two.
The slow pitch in Durban didn't really do him any favours but he bowled an immaculate line and length to pick up 3-16 as England reduced South Africa to 137-4.
Broad really has blossomed into a supreme competitor - he relishes the challenge of bowling sides out and he has the skill and control to do so.
There was one extraordinary over that he bowled to Dean Elgar where he went round the wicket, over the wicket, round, over, but each ball was bang on the spot - that's not easy to do and it just shows the absolute mastery he has over the cricket ball.
|Former England spinner Graeme Swann on BBC Test Match Special|
|"Stuart Broad really seems to relish stepping up to the plate when James Anderson is missing from the attack. He's probably a bit glad because he can get some of the limelight. He bowled beautifully well."|
Thank goodness he has shaken off that ridiculous 'enforcer' tag - there's no need to bowl bouncers; a good, probing line and length can be just as hostile.
In fact, I thought England's attack as a whole demonstrated that principle.
Without banging it in short, they looked more penetrative and hungry than the South African attack, and that's why, if I were to give anyone the upper hand at this stage of the match, I would have to give it to England.
Stokes endures frustrating day
I'm a great supporter of Alastair Cook as England captain but I do think he missed a trick by not reviewing Ben Stokes' lbw appeal against Elgar.
As we know, had England reviewed, the not-out decision would have been overturned and Elgar wouldn't be unbeaten on 67 overnight.
Of course, hindsight is a wonderful thing, but I did think it was a little odd at the time - England had both reviews left, but we didn't even see a huddle form as you usually do in these situations. Cook must have thought Elgar hit it, as umpire Aleem Dar probably did, but Stokes was absolutely convinced.
All in all it was a pretty frustrating day for Stokes, who also had what I thought was a perfectly legitimate catch off AB de Villiers given not out.
As far as I'm concerned it was cleanly taken - we all know the two-dimensional cameras of the review system can't be relied upon for those decisions, so it's disappointing that the umpire didn't have the conviction to give it out on the field.
No problem with cautious Compton
England's total of 303 was underpinned by Nick Compton's measured 85 - and unlike some, I have absolutely no qualms about the sedate nature of his innings.
Yes, he batted slowly, but I thought he played really well - he came in with England having a huge amount to do and held the innings together. It's not the sort of pitch where you can thrash the ball about. It's a slow pitch and it's all about survival and you've got to play with a certain amount of caution.
That's not to say there's no room for improvement - you can always look to be busier or run a few more singles - but overall I think he can feel extremely proud of his effort, and unlucky not to score a century.
His 85 runs could be hugely valuable for England. South Africa have got quite a timorous batting line-up, and if England bowl them out quickly tomorrow, they could put themselves in an excellent position to set up victory.
I wouldn't want to be chasing more than 250 batting last on this pitch.
Jonathan Agnew was speaking to BBC Sport's James Gheerbrant.