Pietersen's crowning glory
Man of the day
When Ian Botham broke Dennis Lillee's world wicket-taking record in his comeback Test in 1986, Graham Gooch famously asked: "Who writes your scripts?" After today's supreme performance, nobody ever needs to pose the same question to Kevin Pietersen. For three years and 39 Tests, KP has been plotting this moment, his glorious return against the country of his birth, and how magnificently he played the lead role. He gave furious notice of his intent back in February 2005, when he lacerated one-day centuries in Bloemfontein, Border and Centurion in a hate-suffused series in South Africa, but this was the innings that really counted. His 13th Test century in his 40th match, but the first that will leave him truly fulfilled.
Nervous starter of the day
"I sure he's going to be hugely motivated to perform well, but I'm sure he'll feel a touch of pressure as well." Graeme Smith was prophetic in his pre-match assessment of Pietersen. Rarely has KP looked so ill at ease in a Test situation - he arrived at the crease with England in the midst of their wobble, and he would have run himself out second-ball for a duck if Makhaya Ntini's shy from mid-on had been gathered cleanly at the stumps by Hashim Amla. Pietersen had progressed no further in his innings when Dale Steyn sconed him with a brute of a bouncer - a helmet-rattler that required a lengthy break for running repairs. But crucially, he endured, and inevitably, he flourished.
Déjà vu delivery of the day
Some might say that Steyn has enjoyed a meteoric rise as a Test cricketer, and with 78 wickets in the past 12 months alone, it's hard to argue with his recent statistics. But for Michael Vaughan, one of only three English survivors from the 2004-05 tour of South Africa, Steyn's abilities have been as unequivocal as a 90mph leg-cutting yorker. That was what he was served up in the second innings of Steyn's Test debut at Port Elizabeth, and both men remembered the moment only too well. Steyn needed only two deliveries to repeat the dose today - and though this version was arguably less venomous, Vaughan's footwork betrayed a man who feared what was coming.
Collapse of the day
It had all been going so swimmingly for England. A century opening stand on a misleadingly sluggish surface, against a South African attack for whom only the veteran Jacques Kallis had located the right line and length. But then, as can so often happen, their progress was stymied by a duff lbw decision, and suddenly the pitch was livid with demons. Andrew Strauss fell first, to a Morne Morkel offcutter that pitched outside leg, before Vaughan attracted the wrath of Steyn. Then to complete a meltdown of three for three in 13 balls, Alastair Cook fended a snorter off the splice, for AB de Villiers to pouch a dolly in the slips.
Serene starter of the day
Ian Bell, by contrast, arrived in the middle with scarcely a care in the world, which is not what the scriptwriters had envisaged. In the assessment of many, not least the South Africa coach, Bell is a man living on borrowed time, odds-on for the chop as and when Andrew Flintoff is ready to reclaim his place. And yet, while Pietersen prodded and fretted in the early moments of his stay, Bell slipped onto the offensive like the mouse that roared. His first delivery, from Steyn, was eased delightfully through the covers for four, and he added four more in 14 balls to reignite England's innings. One of them, admittedly, was rather streaky, but the intent was what really counted.
Decision of the day
When Smith won the toss, he chose to bowl first - a no-brainer on the face of it. After a week of torrential rain, the pitch showed signs of real juiciness, and Vaughan admitted he'd have made the same choice. But instead of a springboard, the track was a bog, and South Africa's pacemen sunk deeper and deeper into the mire in a lacklustre first session, as Strauss and Cook helped themselves to a century stand. A brief glance at the honours board might have changed Smith's mind - he hardly found Lord's a minefield when he made 259 here on his last visit, while England's batsmen had mustered 21 centuries in their last nine appearances. But the die of the day had been cast.
Andrew Miller is UK editor of Cricinfo