England's odd couple
Just as the tourists seemed to be heading for a second slide the batsman Australia fear most and a player who received an MBE for his only previous Ashes Test combined to make them itch. And they did it by attacking.
In the third session the play was so bright it even raised the voices of a subdued Barmy Army, with Collingwood and Pietersen adding a total of 153 at almost 4.5 runs an over. It almost certainly will not save the Test - Australia need five wickets and England 355 runs on day five - but it proved the visitors could stand with the home team. In a match like this they must celebrate small victories
Alastair Cook was the first to improve, displaying the resolve that his senior team-mate Andrew Strauss failed to produce, on a pitch with widening dangers that often forced balls to change course. Defence would eventually end in submission so Collingwood and Pietersen were adventurous once they had befriended the surface.
Australia had enough runs to be philanthropic and the boundaries came freely. Collingwood was strong off the back foot through cover and he improvised against Brett Lee with a glided six over Adam Gilchrist and Shane Warne in the cordon. Warne was also punished by Collingwood when he was lofted over the wide mid-on boundary, but the bowler's greater danger came from Pietersen.
Collingwood's footwork was quick and sharp; Pietersen's reach and height usually detonated even Warne's most troublesome offerings. The opponents have been close friends but there were few suggestions of strong feelings other than extreme frustration when Warne picked up the ball in his follow-through and pinged it back at Pietersen. It struck the bat and riled Pietersen, but not into making a mistake.
Testing his arrogance, Pietersen's opening duels with Warne included three men in the deep on the legside, a short-leg, slip and two close covers. He passed the examination and waited on Warne to drop short or would sweep away the problems. Strong drives were saved for the fast men, who he handled without fear and much discomfort until a final burst from Lee and Stuart Clark in the afternoon shadows. This is the quickest pitch in the country and only Clark, who struck him on the arm, was able to make him flinch.
Warne tried many things and Gilchrist experimented in lieu of the back-injured Ricky Ponting. Fields were changed, encouragement was shouted and a difficult stumping chance was missed off Warne. Pietersen was 80 and added another 12 by the close as he lost Andrew Flintoff, the fourth victim of Warne.
It did not feel like Warne's day, but he started strongly, was over-run when Pietersen and Collingwood joined forces, and resurfaced late. Collingwood helped out by charging inside the line and missed his century by the boundary he was chasing while Flintoff lobbed a ball too full to be pulled. Pietersen remained unconquered and carries England slim chances. There is no question of him shirking his duty.
Peter English is the Australasian editor of Cricinfo