Pietersen delivered the innings the tourists have been yearning with 10 boundaries and two sixes against a Test-strength NSW fast bowling attack to have England in high spirits at stumps on the second day of the three-day practice match.
At the close on Monday, England were 256 for four in reply to the NSW first innings declaration of 355 for nine.
Skipper Andrew Flintoff was at the crease with Pietersen unconquered on 48 off 81 balls with eight fours.
Pietersen, one of England's big batting hopes if they are to retain the Ashes against Australia in the Test series to get underway in Brisbane on November 23, said he has been spending hours in the nets.
"It's a delivery that I haven't had much of at 90mph-plus over the last few months, we've been playing a lot of the sub-continent, so it's a delivery I've worked on and it's a delivery I am working hard on these wickets," Pietersen said.
"If you leave the short ball just to be negative and defensive then you have more opportunity of getting out or being injured, the key is to keep your eye on the ball for as long as possible and sway if you need to.
"At the end of the day you are going to get it, one, two, three or 11 times, you're going to get it and you just have to play it."
Pietersen said England's batting performance Monday was a great tonic ahead of the first Test.
"It was a test today, we've probably got three innings, this one and two in Adelaide (against South Australia next week) before we play the Test in Brisbane so it was important for guys to get in and score a few runs," he said.
"It's a case of acclimatising and getting used to the Australian wickets, different conditions and I think a really big positive from today is the bowling attack we faced.
"You have four possibilities of pacemen in the Australian side, definitely Brett Lee and Glenn McGrath and then Stuart Clark and Nathan Bracken."
Alastair Cook consolidated his grip on the No.3 Test batting position with an impressive 59.
Cook, who scored 214 batting for Essex against the Australians on last year's Ashes tour, played strongly off his pads and the back foot before he was lbw to McGrath.
While Cook flourished, Ian Bell was out for a second-ball duck and missed a great chance to improve his Test chance, with England expected to play four bowlers along with all-rounder Flintoff against the Aussies in Brisbane.
Marcus Trescothick's troubled series lead-up took another turn for the worse when he played on a delivery from Lee and was bowled for eight.
That followed the Somerset left-hander's abject two in last Friday's one-day loss to the Prime Minister's XI in Canberra.
Opener Andrew Strauss had a life on 32 when he was put down by Clark at third slip off Bracken.
But Clark redeemed himself with a freakish caught and bowled to send Strauss on his way for 50. Clark stuck out his right hand on his follow-through and snatched the catch.
Clark struck again two balls later, dismissing Bell for a two-ball duck, probing outside off-stump and caught behind.
NSW declared their first innings on the wicket fall of Bracken for eight.
Steve Harmison picked up the wickets of Moises Henriques (29) and Daniel Smith (45) to finish the innings with 3-95 off 20 overs, while new-ball partner Matthew Hoggard had Nathan Hauritz caught by a diving Ashley Giles at mid-wicket for five.
James Anderson, who has been given the nod by team coach Duncan Fletcher to play ahead of Sajid Mahmood in the first Test, had Bracken snapped up by Trescothick at first slip with the first ball of his 16th over to finish with 2-45.
Rain prevented all but 19 minutes of play in the morning session, cutting into more valuable Test preparation time for the tourists.