Durban - At Kingsmead on Thursday, Proteas skipper Faf du Plessis tried to take Dale Steyn out of the attack at the end of his 16th over.
In the skipper's defence, Steyn had just been hit for back-to-back boundaries and with Sri Lanka 177/8 at the time, Du Plessis would have wanted to wrap things up as quickly as possible.
But if Dale Steyn wants to keep bowling, then good luck trying to take the ball out of his hands.
In a superb effort of high-octane, high-speed fast bowling, the 35-year-old delivered another four overs to finish with figures of 4-48 in 20.
He bowled 10 on the trot after lunch - he says it is just the third time in his career he has done so - and he would have claimed his first five-wicket haul since 2016 were it not for Dean Elgar's sitter of a dropped catch in Steyn's 17th over.
The five-for was not to be this time, but given everything that Steyn has endured since breaking his shoulder in Australia in 2016, this was a spell that well and truly put to bed any doubts that may have remained over his fitness levels.
Steyn's figures for that post-lunch spell read: 10-4-24-2.
Perhaps more encouraging was the fact that, throughout that 60-ball spell, Steyn's speeds never dipped.
On a slow Kingsmead wicket, he comfortably clocked in the 140km/h range.
There is still a lot to do in this Test if South Africa are to secure victory - they lead by 170 with six second-innings wickets remaining - but seeing Steyn in full flight for such an extended period will be as pleasing as any victory for the Proteas brains trust.
Make no mistake, it was not easy.
"Shit, it's hard," Steyn offered with a tired smile and that famous white floppy perched on his head after the day's play.
"I felt that it was going well for me and I told myself: 'I'm not going for any runs and I'm going to just carry on going here until the captain has enough.'
"He had enough after my sixth, but I kept begging and I got what I wanted."
Steyn knows that cricket isn't the most important thing in the world, but being away from the game he loves so dearly with a series of injuries that threatened to end his career has put it all into perspective.
"After not playing for two years it's just a blessing to be able to be playing again," he said.
"I almost feel like I've had to start over and that I'm not on 430-odd wickets, I'm on like 20 since I broke Polly's (Shaun Pollock's) record.
"It was nice to finish a three-Test series against Pakistan and not have someone write that I'm an injury away from retiring. It's nice today to contribute again and I just feel like I've started over."
A key member of South Africa's Cricket World Cup plans this year, Steyn has a lot that he still wants to achieve in Proteas colours.
The talk is that he will bring down the curtain on his white ball endeavours after that tournament, but that he wants to keep going for as long as possible on the Test stage.
"Hopefully this can continue for a wee longer, but I don't know how much longer right now. If I'm bowling 10-over spells then it shows you that I'm enjoying what I do," he added.
"If you had asked me two years ago where the full stop would be, I would have been able to give you an answer. But when you take two years out of it you realise that you don't know what you've got until it's gone.
"It's just fun to be here."
Steyn's four wickets on Thursday mean that he is tied with England's Stuart Broad on 437 as the joint seventh-highest wicket-takers in Test history.
Elgar probably owes him a beer for not getting him to 438, but Steyn is not one to sweat the small stuff.
"Test cricket is hard. Nothing should come easy," he said.
"Fifers shouldn't come easy, and no catch is easy, either."
Play on Friday gets underway at 10:00.