First, Alastair Cook's tourists lost their last six wickets for 61, to be bowled out for 251 before lunch; then came the bombshell, as they took the field for Australia's second innings, that Stuart Broad was unavailable and on his way to hospital for x-rays on a foot injury.
Finally, David Warner (112) took cruel advantage of England's vulnerability with a brutal 127-ball century as Australia piled up 235 for three by stumps, for an overall lead of 369.
Even in the context of this miserable tour so far - in which there have been some awful passages of play for England, including the collapse of six wickets for nine runs to set the tone in Brisbane - day three in Perth was a new low.
It was as if all the effort of the previous afternoon, to try to stay in touch with a superior force, had taken toll as a realisation dawned that they could not after all be competitive.
In temperatures once again soaring above 100 degrees and in the absence of Broad, Warner hit 16 fours and a six on his way to three figures - dominating an opening stand of 157 with Chris Rogers (54).
England missed their opportunity to negate Warner on just 13, when Matt Prior failed to stump him in Graeme Swann's first over.
Rogers also escaped on 26 when the wicketkeeper left a catch to Alastair Cook at slip, but the captain could not react quickly enough to the edge off James Anderson.
The two left-handers therefore raced to the first century opening stand of the series, by either team, and it was already hard to see how England might avoid defeat here - let alone have any chance of victory.
Rogers eventually departed to an aerial cut off Tim Bresnan, and Warner himself - after another missed stumping on 89 - when he launched a skier to long on, safely held by Ben Stokes off Swann.
There was late reward for Stokes' efforts with the ball too, when one nipped back to bowl Michael Clarke yet did not alter England's perilous match situation a jot.
They had earlier lost their remaining frontline batsmen long before the second new ball was available - and despite a modicum of defiance from Bresnan and Swann, faltered tamely.
The tourists have hardly helped themselves, but little has fallen in their favour since their arrival down under eight weeks ago.
Continuing that theme, it seemed the definition of misfortune - with a viable position at that point still not that far from reach - to lose a key batsman lbw via DRS at the WACA, this venue where almost every delivery can safely be assumed to be clearing the stumps.
On that basis presumably, and perhaps a suspicion of bat on ball, Marais Erasmus gave Ian Bell not out pushing forward to a Ryan Harris inswinger.
But Australia felt they could chance a review, under new regulations which reinstate their quota after 80 overs - and to general surprise, Hawkeye simulation depicted the ball clattering into the top of middle-stump.
Mitchell Johnson then struck for the first time in more than 40 overs, counting back to the second Test.
Stokes, perhaps spooked by a delivery two balls earlier which hit a crack and diverted at an impossible angle high past Prior for a bye through the slips, wafted a drive at a wide one to be caught-behind.
Clarke decided on a double-change with the old ball, and Peter Siddle (three for 36) duly came up with another wicket - Prior going for the pull but managing only an under-edge behind.
England had lost three for 27 - and with only the tail left, their chances were already fading fast.
Bresnan greeted the second new ball with the second and third of three cover-driven boundaries in the same Watson over. But Johnson made short work of Broad, forcing him back in the crease and then pinning him lbw with a full delivery on to the right boot barely an inch or so in front of the stumps - injuring him for good measure.
Bresnan was then ninth out to the admirable Harris (three for 48), caught-behind even as he tried to leave another testing delivery, and Swann was left unbeaten when Anderson fended a catch to short-leg off Siddle.
It was a hapless end to the innings, and the preface for much more punishment to come.