England finished day two of the fifth Test in a strong position despite the late wicket of Kevin Pietersen.
Pietersen hooked Mitchell Johnson straight to Michael Beer but the dependable Alastair Cook and nightwatchman James Anderson guided England to 167 for three at the close in reply to Australia's 280 all out.
That Australia got close to 300 was thanks to some late-order hitting from Johnson (54) and Ben Hilfenhaus (34), while Andrew Strauss crunched 60 off 58 balls to give England's reply its impetus.
The tourists must merely avoid defeat here to become the first England team to win an Ashes series in Australia since 1986/87.
Australia began a cloudy morning on 134 for four, and it seemed they needed a substantial contribution from at least Michael Hussey or Brad Haddin.
Instead, Haddin went tamely in only the fourth over of the day -- chasing a wide ball from Anderson (four for 66) and edging behind on the back foot.
Hussey kept England at bay until Paul Collingwood struck with the final delivery before the second new ball was taken.
Collingwood tried a different tack with the sixth ball of the over, a tighter line and a touch of inswing to the left-hander who inside-edged on to the top of his stumps in defence.
Chris Tremlett was unlucky to see his second over with the new ball go for 11 runs. But Anderson exacted swift revenge on his behalf, when Steve Smith edged to Collingwood at third slip.
Four balls later, more outswing brought Anderson his 20th wicket of the series -- Peter Siddle edging obligingly to first slip. Johnson and Hilfenhaus were in no mood to go quietly, though, and England appeared to run out of ideas while the former was clubbing five fours and a six in his 63-ball 50.
Hilfenhaus hoisted a six off Tim Bresnan, and Johnson added a four and another maximum in the same favoured direction at the start of the next over from Graeme Swann.
It was therefore a significant relief to England when Johnson lost his off-stump to Bresnan (three for 89), and Hilfenhaus was eventually last out -- caught by Matt Prior off Anderson.
With swing and occasional uneven bounce in the equation, stand-in Australia captain Michael Clarke handed Johnson the new ball, but Australia mostly bowled too short.
Strauss was especially fluent on his way to a 49-ball 50. Australia hit back though -- Hilfenhaus bowling Strauss and Jonathan Trott going for a duck.
Thereafter, Cook made it his business -- in company with Pietersen -- to continue an accumulation which has already brought him more than 600 runs in this series.
The partnership was almost cut short as it moved towards 50 when Cook went for a big heave off debutant Beer, with Hilfenhaus accepting a simple chance at mid-on, but it was a no-ball.
Both Cook and the partnership moved past 50 soon after, before a scrambled single off Beer took the opener to 5,000 runs in Test cricket -- the second youngest man, after Sachin Tendulkar, to achieve the feat.
But Australia belatedly got their breakthrough as Pietersen top edged a hook shot off Johnson and Beer held a consolation catch at deep backward square.