The showman returns as he always promised

And just like that, it was as if he'd never been away. Kevin Pietersen had waited 21 months and 39 first-class innings for the chance to charge through for that manic quick single, to punch the air with the self-satisfaction of old, and break a hoodoo that had hung over him almost since the day he lost the England captaincy back in January 2009. By the time a downpour came to Australia's aid, he was striking the ball with presumptuous ease, playing like a man restored to the plinth from which he had toppled, and ready to make his favourite foes pay for the indignities he'd endured since he was last in such a position of dominance.

At face value, it all looked so laughably predictable. After all the agonising and pontificating, the doubts and column inches, Pietersen did what everyone, deep down, believed was his destiny, and turned in a performance that might have been lifted from one of Ian Botham's scripts from the 1980s. With the one hand it provided closure, as a grim chapter of KP's career was officially put to bed, while at the same time he set about carving a fresh new set of wounds for Australia - a team whose biggest weakness, no matter what how great or vulnerable the players therein may be, comes when they are challenged eye to eye by a player they both respect and fear.

The only oddity about Pietersen's performance was its context. The last time we saw him lapping up the acclaim for a hundred, at Trinidad in March 2009, the cult of KP was the central theme of the innings, just as it had been for each of 15 previous centuries that he'd racked up in his career, starting - of course - with that bewildering feat of ego-mania that sealed the Ashes at The Oval in 2005.

Here he was, back at the Adelaide Oval, the scene of a contest four years ago so brimful of hubris that it might have been his career in a microcosm. After his first-innings 158 and his triple-century stand with Paul Collingwood, Pietersen had memorably stated that he'd got the great Shane Warne mastered. Three days later, Warne bowled him behind his legs for 2, to set in motion the mother of all Ashes collapses.

This time, however, he tempted no fate and sought no extra attention, other than the requisite celebration pose that is sure to adorn the back pages of the British newspapers. "It's wonderful to get runs, and it's wonderful to put the team in a position where we can win a Test match in Australia," were his first words as he addressed the press afterwards, which wasn't an especially extraordinary thing to say, but notable nonetheless for its humility. Here was just another England cricketer checking in for duty, and you could almost hear Andy Flower's pencil going "tick" in the requisite box. Oh good, KP's back to form. We're one step closer to our goal.

The question of whether Pietersen buys into that collective goal is one that has stalked his career from year dot, and has been a particular obsession for Australia ever since his lone ranger performance in the 2006-07 whitewash. At Perth, as the last rites of England's miserable Ashes defence were being played out, Pietersen's disdain was self-evident as he prodded singles from the first deliveries of four of the last six overs, and left his lower-order colleagues to be scythed down by Warne. He was most certainly a man apart in that series, a brooding presence whose personal excellence could do nothing to nothing to halt the juggernaut, and once the series was gone, his interest went with it. Of his tally of 490 runs, 408 came in those first three games.

It's different now for Pietersen, because it has to be. His downturn in personal form happens to have coincided with an upsurge in England's collective ambitions, and whether or not that was a coincidence at the outset, it has become a fact of his career that he has had to deal with. The world ceased to revolve around him at the very moment that he was sacked as captain for his insurrection against Peter Moores, and he's spent a few months feeling giddy while getting used to a new gravitational pull. In the circumstances, who wouldn't?

All the same, John Buchanan and Warne still delight in trumpeting the notion that he is an "outcast" within the England squad, and while KP could only offer a perplexed "Who? No" to an enquiry on that subject from an Australian journalist, a more resounding endorsement of his new-found credentials came moments later, when he walked back into the visitors' dressing room to a raucous whoop of "Here he is. Yeah!" from his cock-a-hoop team-mates.

Pietersen may never be the easiest man to warm to in the England squad, but there's little question how valued he is within the walls of the dressing-room - not least because of the menace his record brings to their collective presence on this tour. Like Botham and Andrew Flintoff before him, he is a lightning rod for the pressure that Australia seek to impose on their oldest enemy, precisely because they recognise him as the biggest threat to the status quo.

Everything about Australia's preparation for this series centred around Pietersen and his new-found "vulnerability". At a pre-series press call in Brisbane, player after player obsessed about his talent and the need to keep him in his box, allowing the lesser lights in the line-up - Ian Bell in his only innings at the Gabba, and most especially, Alastair Cook - to sneak round the blind-side and swarm through the gaps. The selection of Xavier Doherty, on account of Pietersen's recent failings against left-arm spin, is already looking like one of the most futile attempts at man-to-man marking since Maradona took on the entire Belgian midfield in World Cup 86.

The only reason Doherty ever looked likely to ensnare Pietersen was that he had been padded up in the dressing-room for 11 straight hours before Jonathan Trott finally deigned to end his 502-run stand with Cook and give England's gun batsman a chance to get to the middle. "I found it more tiring waiting to bat the other day than batting today," said Pietersen. "You could probably see by the way I started... I was trying to get to fifty in five balls. But it was brilliant to watch, it's brilliant to see and long may it continue for all of our batters to be in nick, because we will win a lot of Test matches if our batters are in good nick like this."

Pietersen is, as he admitted, a man for the big occasion. The last time he played this well was at the World Twenty20 back in May, a contest in which he was named Man of the Tournament as England captured their maiden global title. But the success on that occasion came at a price, as the gains he'd made with his patient approach to Test cricket in Bangladesh were scattered in a cloud of delinquent slogging. It left him unready for a singularly tricky home campaign against Pakistan, and left him in a scramble to find his form for the Ashes.

But find it he has, with a busman's holiday to his place of birth, Natal, giving him a chance to work with his original mentor, Graham Ford, who has known his game since his earliest schooldays. While Pietersen would not divulge the exact nature of the work they had done, a major feature of his innings was the clarity of his leg-side play, with a huge proportion of his first fifty runs coming in a flood of flicks through wide mid-on. His game brain has been reprogrammed, and having "done his head in" with the number of starts he had squandered in the past 21 months, he was not going to let this opportunity pass by.

"The key to what I've done is the little things that I've worked on," he said. "When you are batting for that amount of time you find a pace where you go through the gears to fifth, then back down to third and if needs be drop back into first and then go back up. It's something I've worked hard on and it's what the team needs and that's how we play it, we're not looking at two or three sessions ahead, we looking at ten minutes, ten run partnerships, hours and keeping things simple."

What the team needs is what the team gets in this current England set-up. Even the outcast has bought into that.