Never mind that it was South Africa's first day-night Test or among Adelaide's most social events. Never mind that the Australians were facing their first whitewash at home. Never mind that they hoped to avoid that by making five changes including three debutants, a colour-blind wicketkeeper who last played Test cricket three years ago and a third seamer playing his sixth Test in four years. This was always going to be about Faf du Plessis.

Convicted chewer of mints and user of fresh-smelling saliva to shine the ball. Charming stand-in captain who continues to claim innocence. Centurion at this venue four years ago who ground down Australian morale and changed the momentum of the series. November 24, 2012 was the date he made 78 on debut; November 24, 2016 was the date he made a century on the road to redemption. If South Australia was looking for a new public holiday, they may be interested in a du Plessis' day.

That is not as far-fetched as it seems. At the end of the first day of this Test, Adelaide loved him as much as he loves it.

The cheers outweighed the boos when du Plessis ran to the Riverbank Stand in celebration of his second century at this venue. With the setting sun, the soft light creating a halo of the clouds, the scene should have been romantic, but du Plessis assaulted the cool evening air with a volley of punches. Most of them would have been instinctive acts of achievement; some of them were aimed at the armchair executioners, who labelled him a cheat and wrote him off as an opportunist after the Hobart Test and the ball-tampering bluster.

Several of them were in attendance when du Plessis walked out to bat, with South Africa stumbling on 44 for 3. He was greeted with a chorus of condemnation that followed him to the crease, where a much bigger job than clowning around with the crowd awaited.

Stephen Cook, South Africa's most unsure batsman on this tour, had faced 51 balls, most of them uncertainly. He was lucky to be there at all after being reprieved by a no-ball and was fighting his own battle. Someone else needed to fight South Africa's. The same someone who has fought it throughout the series. The skipper.

Australia were more up for it than they had been since the opening day in Perth, even with different personnel. Jackson Bird found the right length for the first time when he drew an edge from du Plessis but it fell short of the cordon. Mitchell Starc exploited the bounce and got du Plessis to fend one into his ribs but the only damage that was done was to his eardrums when he was booed (again) after retrieving the ball and handing it back to the bowler.

When du Plessis did that against Australia before, at home during the 2014 Test encounter, they took such exception that he said they were as territorial as "a pack of dogs". This time the opposition didn't say anything but their supporters did. They hounded du Plessis with hostility without realising they were helping him along.

His flick and drive came out early and he had scored 20 runs from his first 19 deliveries, unusually quick for a batsman who is known to take his time. He slowed against the spin, especially after Nathan Lyon beat the inside edge with one that ripped back in.

The early turn would not have worried du Plessis as much as it would have encouraged him, knowing Tabraiz Shamsi was on hand to make use of it later. His declaration with 12 overs remaining in the day was nothing if not sporting but it would not have been possible if he hadn't scored the runs that allowed him to end the innings early.

Du Plessis was the only South African who had some measure of the movement - and there was plenty with the pink ball - and the only one who really had something to prove, besides Cook. In hindsight Cook's 40 was worth a lot more than it seemed when he offered a catch to Steven Smith at second slip and succumbed to Starc. Cook's was a demonstration of determination; du Plessis' was one of defiance.

By the time he got to fifty, he'd had his fair share of fortune. Three edges had fallen short and he saw a drive burst through Bird's hand as the bowler followed through. He was booed and cheered in equal measure and raised his bat without much fanfare. At 130 for 5, South Africa were still in some trouble and they were down to their last recognised pair. Nineteen runs later, Australia were into the tail but now du Plessis stepped up.

He started playing the ball later and trusting his timing more. He cut with confidence and forced Australia to bowl full, eventually to overpitch, then he treated the Adelaide audience to the best drives they saw all day. Both were off Josh Hazlewood, both on the front foot, both through the off side and together they took him a shot away from a second century at this venue. He needed more, though, and lost Kyle Abbott in the process, but paddle-swept and sprinted a brace with Kagiso Rabada to earn vindication. Amid the boos, the appreciative applause filtered through.

It was not the same kind that du Plessis got four years ago, when he topped up on the first-innings 78 with a fighting 110 not out to draw the game. Then, Australians were in awe. This time, his effort was far feistier and the locals were entertained and annoyed all at the same time. More so when du Plessis took the attack to them after the milestone, with a plan to try and unsettle Australia by putting them in at the end of the day.

That move may turn out to be prematurely arrogant but, as things stand, it spoke of du Plessis' chutzpah as a captain. It is a job he may be doing for the last time in Tests, with the return of AB de Villiers' imminent. That also meant, as much as du Plessis was playing to make a point, he was also playing for his place.

A South Africa middle-order of de Villiers, du Plessis and JP Duminy reads like a dream but there is only really space for two of them. Du Plessis and Duminy know as much from last season when they took turns being dropped. They have both scored runs in de Villiers' absence - Duminy 88 against New Zealand, du Plessis 112 not out, Duminy 141 against Australia, du Plessis 118 not out - and they are both making telling contributions as seniors. At some point someone will have to make a choice between them but for the rest of this series, never mind all that.