Australia finally separated Alastair Cook and Jonathan Trott before tea on Saturday but not before the pair had reasserted England's iron grip on the second Ashes Test after an early setback on the second day.
Unbeaten on 90 at the break, Cook looked unmovable at the crease alongside Kevin Pietersen, who had made 14 not out to help England to 198-2, 47 runs behind Australia's first innings total of 245.
After England skipper Andrew Strauss was dismissed on the third ball of a blistering hot day at the Adelaide Oval, Cook and Trott picked up where they left off in their unbeaten stand of 329 in the first test. When Trott was caught by Clarke off Ashes debutant Ryan Harris for 78, the England pair had combined for a total of 502 runs over the two tests.
Doug Bollinger gave the hosts a dream start by clean bowling Strauss for one run in the first over.
Thereafter, though, the revamped Australia strike attack of Bollinger, Harris and Peter Siddle laboured on a flat pitch in temperatures up to 37 degrees Celcius. Bollinger almost had a second scalp when Trott, on 10, sliced a drive to gully but Mike Hussey failed to hold a low catch.
Trott had already survived an earlier scare after a mix-up with Cook when he was on nine, but Xavier Doherty missed a direct hit would have run the batsman out.
Cook was the first to reach his half century with three runs off Bollinger and Trott joined him three deliveries later with a four to midwicket. He got a third life when the ball nicked his glove but wicketkeeper Brad Haddin spilled a high catch.
Cook's one real scare came when was given out caught behind off Siddle when he was on 65, but he confidently demanded a review of the decision and television pictures confirmed the ball had grazed his upper arm.