After Jonathan Trott (83) and Alastair Cook (81) softened up the Australian Invitational XI attack at the SCG on day two of England's final warm-up match, Pietersen did not need to be anywhere near his best to add 57 of his own in quick time as England replied to 304 all out with 302 for five by stumps.
While both Trott and Cook were clearly frustrated to give away their hard work, in an important second-wicket stand of 143 after the early loss of Michael Carberry, Pietersen betrayed a more prodigal approach to batting against inexperienced bowlers.
Twice, he tried a prototype reverse-ramp shot at young leg-spinner James Muirhead - failing to make intended contact on both occasions - before being well-caught in the deep off the same bowler by substitute fielder Dan Hughes.
Despite just one previous innings on tour, and a score of eight on that occasion in rainy Hobart, Pietersen did not appear to be putting too high a price on his wicket in unexacting circumstances.
Trott already had a hundred to his name on tour, in Perth two weeks ago; yet his evident annoyance after edging Josh Lalor behind spoke volumes for the contrasting minds of England's two South Africa-born batsmen.
"I think Kev's pretty unique in the way he goes about his game and thinks about it, but it's always nice to see him in full flow and being confident even in warm-up games," said Trott.
"It doesn't really count now, what the guys do. It's all about being ready and right for Brisbane on that first day.
"The way Kev goes about it might be different to someone else, but he looks in good form to me."
Pietersen was also able to demonstrate his physical well-being, following last weekend's cortisone injection in his problem right knee.
"He seems fine. I haven't heard him complain about it," added Trott.
Much, in fact, appears in order for England - albeit after a rain-wrecked match in Tasmania against Australia A last week, and now against callow opposition.
Steven Finn finished with a flattering five-wicket haul, and Stuart Broad four for 37 in 24 overs as the Invitationals collapsed from an overnight 271 for five.
The tourists' batsmen, Carberry apart, then clicked again.
Trott said: "Everyone has got a few runs, and is feeling good about the game. But you're not going to know exactly what nick you're in until you're in front of 40 or 50,000 people at Brisbane.
"It's more about getting prepared mentally for that, being ready for the challenge and a tight-knit unit.
"Everything seems to be coming together at the right time."
England's number three took issue with the suggestion there might have been some easy pickings, on a very good batting surface.
He added: "It's quite a new-ball wicket. It does seam around a little bit with the new ball, so that's been crucial.
"This morning, the ball was 10 overs old and still doing a bit."
He insists an attack comprising four frontline bowlers with only 12 first-class matches to their names collectively nonetheless provided a significant test.
"You're not going to face the Australian A side every week.
"You're going to have to face state cricketers - and obviously with Sheffield Shield games going on, it's a bit tricky.
"I think we were pretty happy with this standard of bowling, three young seamers who ran in all day and were wanting to impress.
"They were a lot better than what people described. They gave us a good challenge.
"It's a good batting wicket, and when the ball was new they did cause a few problems. I played and missed at one or two early on ... but Cookie and I managed to get through that tough period."
That, perhaps, was why he swished his bat in annoyance when he fell short of a century and walked off holding the blade rather than the handle with both hands behind his back.
He said: "As a cricketer, you have self-pride and want to get out there and do as well as you can every time - not just the Test matches.
"I felt I was in good form, and played at a ball I probably shouldn't have - so that's why I was disappointed.
"You want to go out there and play a perfect innings all the time. But you are going to make mistakes. Today I did, and paid for it."
There were signs, however, that the technical changes Trott has made - after a modest run of scores last summer - are starting to take effect.
"It's ongoing ... it's just finding out a few things," he said.
"The way I've been moving at the crease is important to me, and something I've been working at.
"I'm really happy, but wish I could have gone on to get three figures."
- Sports & Recreation
- Jonathan Trott
- Alastair Cook