England's bowling attack continued to maintain a stranglehold on Australia's batsmen in the fourth Test on Tuesday, putting the tourists on the brink of a first successful Ashes tour triumph in 24 years.
Needing 415 runs just to make England bat again, Australia's brittle top order disintegrated under pressure once again, limping to 169-6 at stumps in front of a despondent crowd of more than 68,000 at the Melbourne Cricket Ground.
Australia, who were bundled out for 98 in the first innings, trail England by 246 runs and are odds-on favourites to become the first team to surrender the Ashes on home soil since Alan Border's defeat to the Mike Gatting-led England team in 1986/87.
Brad Haddin (11) and Mitchell Johnson (6) survived the last few overs to stumps and face the unenviable and virtually impossible task of staving off England's victory charge on day four.
Tim Bresnan, called into the side for Steve Finn, took three wickets in a brilliant spell after tea to leave Australia reeling on 104-4 before Graeme Swann and James Anderson took a wicket apiece to inflict further pain on the hosts.
One of Bresnan's wickets was Australia captain Ricky Ponting, who struggled to 20 before chopping onto his stumps, continuing a woeful run in a series in which his highest score remains an unbeaten 51 in the drawn first Test in Brisbane.
Ponting apologised before taking the crease for his ugly remonstration with the umpires on Monday over a video referral, but no amount of mea culpas are likely to save the 36-year-old's captaincy or win forgiveness from a shattered Australian public for his team's performance.
He stands on the verge of becoming the first Australian skipper in more than 100 years to lose the Ashes three times and after scores of 10, 1, 12, 9 and 0 in his five previous innings, can no longer lean on his batting record to justify his tenure.
Australia's bowlers, to their credit, had earlier raced through England's last five wickets for the addition of 69 runs to have the tourists dismissed for 513 just before lunch.
Any hope of the attack's performance inspiring the team mates with the bat were soon dashed when Shane Watson enhanced his reputation as one of the worst runners in elite cricket by running out opening partner Phillip Hughes for 23.
The pair had made a bright start, notching 50 runs at a rapid run rate of more than five an over, before Watson pushed to cover and called Hughes through for a single that was never there.
Jonathan Trott, whose unbeaten 168 earlier put England in complete command, swooped on the ball and flung it low and straight to wicketkeeper Matt Prior, who whipped off the bails with Hughes short of the crease.
The dismissal was a repeat of the run out in the second test in Adelaide when Watson ran Simon Katich out on the fourth ball of the first innings, though there Trott made a direct hit.
Watson and Ponting helped Australia stutter to 95-1 at tea but rarely appeared comfortable at the crease and both soon lost their wickets to Bresnan.
The replacement quick trapped Watson lbw for 54 before removing Ponting, then Mike Hussey for a duck (0) when the middle order batsman pushed a delivery that stayed low to short cover where Ian Bell took a smart catch.
Michael Clarke, who has managed one half-century in the series, scratched around unconvincingly for 13 runs in a 66-ball knock before nicking a Swann delivery to England skipper Andrew Strauss at slip.
Steve Smith survived a little longer but was bowled by James Anderson for 38 to leave the hosts reeling at 158-6.
Australia's woes had earlier been compounded when paceman Ryan Harris hobbled off the ground with an ankle injury after stumbling in an aborted run-up bowling to Bresnan.
A team spokesman later said Harris would likely need surgery for a stress fracture, casting doubt on his availability for the the fifth and final test in Sydney next week.