Talking to the camera at the midpoint of 24 Hour Party People, Steve Coogan sets the scene for the reinvention of Factory Records and New Order after the death of Joy Division's Ian Curtis: "F. Scott Fitzgerald said there are no second acts in American lives. Well, this is Manchester, and we do things differently here. This is the Second Act."

At the end of the 2016 Hobart Test against South Africa, Australia's fifth consecutive loss, neither Mitchell Marsh nor Nathan Lyon had much reason to believe their international scripts had too much further to run. As a No. 6 batsman, Marsh had been a failure, part of an extended run of middle-order collapses that also swallowed up Adam Voges and Peter Nevill. Lyon, meanwhile, had followed up an underwhelming tour of Sri Lanka with a first-class wickets drought that ultimately lasted all of 110 overs.

By the time Australia's squad reassembled in Adelaide, Marsh was no longer a part of it, and Lyon was reprieved only by the fact the man the selectors wanted, Steve O'Keefe, had suffered a hamstring strain. Lyon came even closer to losing his place for the next Test in Brisbane, where only a last-minute change of heart had him retained in place of a fourth seam bowler in Chadd Sayers.

How this pair came to play vital roles, a little more than 12 months on, in what is turning into a domineering display by Australia in spite of a Durban pitch designed to blunt them is a model lesson in reinvention. Over the course of that journey, Marsh and Lyon have emerged not only as greatly improved players but also as leaders on the field, capable of turning a tide, not just being swept along with one. Circumstances helped at times, too.

For Marsh, a shoulder injury robbed him of the ability to bowl for some months, taking him out of Australian reckoning and simplifying what he could train for. That clarity was useful as he set about remodelling his game with the help of the former West Australian batsman Scott Meuleman, spending hours working on developing his back foot game, strengthening his defence, and softening his hands to prevent nicks from carrying. During the first bracket of this innings on an overcast day one, Marsh edged more than one delivery along the ground - the sort of luck a good batsman makes for himself.

"He was certainly the difference in the two innings. Take his score away there, batting at six ... we were about to break through, about to make them sweat a bit and he comes in and basically scores a 100. That's huge" AB de Villiers on Mitchell Marsh

In addition to the technical, there was also the mental. Very few elite batsmen in the history of the game have managed to make big scores consistently without finding a routine that involves switching on and off between deliveries, typically refocusing at the moment the bowler is at the top of his mark and not a nanosecond before. With help from Western Australia's coach Justin Langer, Marsh said he had found his ways to do so, and it is certainly working: only twice before he was dropped had Marsh survived more than 100 balls in a Test innings; since his recall he has done so four times out of five.

"I've worked extremely hard on my defence, keeping the good balls out and at any level of cricket that's what you have to do," Marsh said. "And I think that's given me a lot more confidence now to be a lot more patient and choose the right balls to play shots at. I think that's really helped me mentally batting wise, so that's pretty much all I've done.

"I used to be quite intense at the crease, every ball. And it wears you out when you do that for a long period of time. I probably can't repeat some of the stuff I think about on the field now when I'm batting in between balls, but I try and keep my mind clear and switch on when the bowler is at the top of his mark and it seems to have helped me."

Batting at the other end, Mitchell Starc took great heart from the transformation, the harnessing of a talent that for a while had seemed capable of wasting away. "Unbelievable, the confidence he's got now is great for him," Starc told SEN. "He's put a lot of big scores on the board in the last six months and it showed across the last two days, he's got confidence in his defence and he hits the ball harder than anybody in the world, it's a joy to watch, I'm glad I don't have to bowl to him because he smacks the ball that hard."

Mitchell Marsh celebrates a vital half-century AFP

While Marsh fell four runs short of a third Test hundred in four matches since his return, his innings was utterly pivotal to the day, and continued an Australian theme of middle-order stability and composure since the start of the Ashes. As AB de Villiers so astutely observed: "He was certainly the difference in the two innings. Take his score away there, batting at six ... we were about to break through, about to make them sweat a bit and he comes in and basically scores a 100. That's huge. He's had a big impact in this game and we'll have to find a way to keep him quiet for the rest of it."

Things were quiet in the early part of South Africa's reply, with the exception of Australian players ambushing the stump microphones with a word or three for their sponsors. The ball was not swinging, nor bouncing too much, and both Dean Elgar and Aiden Markram looked comfortable enough under a brightening sky above Kingsmead. In late 2016, Lyon had struggled to have an impact without the help of scoreboard pressure, to the point that South Africa's middle order had bullied him.

But in the intervening months he had worked assiduously with his mentors Darren Berry and John Davison to improve his method on slow surfaces, specifically for the challenge of India and Bangladesh last year, but more broadly to win the confidence of his captain Steven Smith, his coach Darren Lehmann and the rest of the Australian team. Lyon emerged from those sessions a more worldly bowler, and when he proved to himself and others he could adapt successfully in Asia, his confidence grew immeasurably.

"His last 12 months have been amazing and what he brings to this team is great," Marsh said of Lyon, "So the way he bowled today, the way he's bowled over the last 12 months, you know he's always going to have an impact on the game. And teams know that now … he's one of the best spinners in the world right now, so it's a great weapon for us."

"Lyon is now capable of swarming all over an opponent from the first ball, much as Graeme Swann did for England at his best, and of course Shane Warne did at length for Australia"

That was certainly the experience of Elgar and Hashim Amla in Lyon's first over, when he summed up conditions almost instantly, turning a quicker ball past the left-hander first up, then tossing another delivery higher and straighter to find grip, a leading edge and a sharp return catch. Amla, who had once helped Graeme Smith end the career of another Australian offspinner in Jason Krejza, was trapped on the crease by Lyon's combination of pace, loop, spin and bounce, squeezing a catch to an exultant Cameron Bancroft.

Lyon is now capable of swarming all over an opponent from the first ball, much as Graeme Swann did for England at his best, and of course Shane Warne did at length for Australia. He is also of extreme threat to left-handers, to the extent that their concerns about him can cloud the mind as much as the deliveries themselves can challenge the bat. While de Villiers handled his first three balls from Lyon with an aplomb he would maintain through the afternoon, the arrival of Quinton de Kock offered the Australian another opportunity to spin the web he had cast on England.

Not much can illustrate the contrast between 2016 and this week, mentally and technically, quite like this encounter. Back then, de Kock was arguably the player of the series, and his domination of Lyon was central to it all. This time around, it was Lyon full of confidence and poise, while de Kock has been through an extended run of outs. Rather than being able to attack Lyon with his former impunity, de Kock trudged through 16 deliveries with only a single scoring shot to show for it, and finished by going back when he should have come forward to be bowled past a tentative defensive stroke.

Australia's celebrations of the wicket were raucous and rightly so - it was the opening of an end opposite de Villiers that they were seeking, and the remainder of the South African innings went down in a fearful rush to Starc, Josh Hazlewood and reverse swing. While this Test match, like the careers of Marsh and Lyon, has a Second Act ahead of it, the reverberations of this day and its key players will take an almighty effort to overturn.