Somerset 42 for 2 trail Surrey 317 (Pietersen 163, Mahmood 4-62) by 275 runs
What is that old line about death and taxes being the only two certainties in life? By lunchtime today, most if not all of those present here would have added 'a Kevin Pietersen century before tea' to their list - and been proved right with five overs to spare.
Batting was not straightforward on a relaid pitch, especially during the morning session when the new ball seamed and swung enough to excite Somerset's pace attack, but the man whose England career is on hold (at the very least) did what had to be done: he battled through.
From then on, it became a case of how many runs Pietersen would score, whether colleagues would hang around long enough for the visitors to post a truly commanding total and when, or if, Surrey's extremely special No. 4 might lose interest and give his wicket away.
The answers, in the same order, were: 163, from 168 balls with three sixes and 20 fours; not really, because while a return of 317 looks more than handy on a surface which should take a fair bit of turn and may produce increasingly variable bounce, the visitors might have climbed to 400; and not at all, despite taking a blow to his left hand after going beyond 150.
Although Pietersen was last out, having arrived in the middle this morning with his side 44 for 2, he perished trying to do nothing more exotic than defend against Sajid Mahmood, Somerset's loan signing from Lancashire. He had batted for four hours but clearly wanted yet more time at the crease.
No-one should need reminding but if there were any doubters among the 2,000 or so spectators here today then Pietersen gave them a good old nudge: this is someone in a different class to most who play this game.
Yes, there was power - paceman Peter Trego and spinner George Dockrell were both hit for sixes. But mostly this innings will be remembered for its certainty and control. Good balls were defended with great respect while almost everything even remotely inviting was put away with crisp authority. Those who witnessed Pietersen's double century against Lancashire at Guildford in mid-July say the two knocks were similar in that there, as here, he never went into overdrive but still scored at a rapid rate.
Having been booed to the crease in Hampshire a week or so ago and then jeered all the way back after making a first ball duck in a CB40 game against his old county, Pietersen was politely applauded when he made his entrance here - and given a long and deservingly warm hand on completing the 45th first-class century of his career.
How much this hundred meant, only the man himself will know (and he continues to reject media requests in the wake of his fall-out with England). But he raised his bat to the dressing room, then acknowledged the crowd's generous response before pumping his fist two or three times - not in a showy, 'look at me' kind of way but simply, it seemed, to underline his pleasure. A hug with batting partner Gary Wilson came next, followed swiftly by another driven four off Alfonso Thomas.
"He's looked as good here as he ever has," said Surrey's team director, Chris Adams. "We've seen him hitting the ball really well in the nets and it is great for him to have gone out there and played as well as he has today.
As Adams pointed out, with a couple of balls having already gone up and down (Stuart Meaker was bowled by a low one late in Surrey's innings) the pitch "was not all in favour of the batsmen". And Pietersen, given all that is going on and with a crucial meeting with England captain Andrew Strauss coming up at some time, might not have been in the mood to play himself in.
No chance, apparently. "He has been superb in our dressing room and worked very hard," said Adams. But how is Pietersen away from cricket? "There are unresolved issues and the sooner there is a solution to those issues the better for everyone, Kevin in particular," added Adams. "My job is to focus on Surrey and make sure he is in the frame of mind to deliver."
As for Somerset, they could have done with facing a fully focused Pietersen like a hole in the head. After a weekend of woe - losing out on Twenty20 Finals Day yet again and then being eliminated from the CB40 48 hours later - they must win this match to have any hope of challenging hard for that elusive Championship title.
The hosts kept 10 of their opponents on a tight rein with only their former all-rounder, Zander de Bruyn, going past 30. And he didn't make many more than that. But Pietersen dominated them so completely that the loss of openers Arul Suppiah and Marcus Trescothick before the close came as no real surprise.
A win here should secure Surrey's Division One status. One thing is already certain, though: they are the only winners out of the rift between England and Pietersen.