Australian opener Chris Rogers said Sunday England's faint Ashes hopes were set to disappear down widening cracks at the WACA Ground after the home team took a stranglehold on the third Perth Test.
England were left bruised and all but beaten after what Rogers described as Australia's best day of the series, and potentially their most important as they close in on claiming the Ashes for the first time since 2007.
Australia led by 134 runs on the first innings after the England tail folded meekly again before lunch on the third day and the tourists were dismissed for 251.
The Australians were 235 for three in their second innings at the end of play for an overall lead of 369, with Shane Watson on 29 and Steve Smith on five and two days left to play.
"I don't think we could be in a better position," Rogers told reporters after the day's play.
"To finish day three 370 in front, that's position A.
"Today was an amazing day, probably as good a day as we've had in the Ashes so far."
Rogers, who was hit on the body by a ball from Ben Stokes that jagged back off one of the cracks that have opened up in the extreme heat, said it would make the pitch tougher to bat on over the final two days.
"All in all it's a good surface, but these cracks are going to come more into play," he said.
"If these cracks keep widening, then it's going to be very hard to bat on, and a little bit scary."
Rogers' fellow opener David Warner (112) capitalised on the shoddy wicketkeeping of Matt Prior, who missed two stumping opportunities from the left-hander, to post his second century of the series and take his tally for the series to 457 runs at 91.40.
Australia lead the five-Test series 2-0 after comprehensive victories in Brisbane and Adelaide and can regain the Ashes with victory in Perth.
As if England's predicament wasn't already dire enough, the tourists returned to the field for the Australian second innings without their best fast bowler Stuart Broad, who is awaiting the result of scans to determine the extent of a foot injury.
Broad injured his right foot when struck by a swinging yorker by Johnson, who may have delivered the final blow to England's hope of hanging on to the Ashes.
Broad was trapped lbw by the delivery for five, and limped to a fitness test in the nets between innings before being taken from the ground for scans.
Broad was on crutches at the post-match press conference and said he would not be able to bowl again in the match, but would bat if required.
He said he was unsure of the extent of the injury, and was still hopeful of playing in the remaining two Tests.
"Something showed up on the X-ray, but it was a bit inconclusive, so I had to have an MRI," he said.
"We are just waiting on those results."
Broad conceded it was a disastrous day for the tourists. "It was a bad one, there is no hiding from that," he said.
To add insult to injury, the embattled Prior -- who again failed with the bat earlier in the day -- gifted Warner a life when he missed the easiest of stumpings in spinner Graeme Swann's first over of the innings.
Warner was on just 13 and was beaten in flight by Swann but Prior failed to take the ball.
Prior's afternoon went from bad to worse when he then failed to react to a thin edge from Rogers, on 26, from the bowling of Jimmy Anderson.
Prior missed a second opportunity to stump Warner off Swann when the Australian was on 89.
Warner's 140-ball knock finally came to an end when he holed out to Stokes at deep mid-on from the bowling of Swann, having hit 17 fours and two sixes.
He and Rogers put on 157, the first century opening partnership of the series, before Rogers fell to Tim Bresnan for 54.
Earlier in the day, England resumed on 180 for four, but offered little resistance to the Australian pace trio of Ryan Harris (3-48), Johnson (2-62) and Peter Siddle (3-36).
The last six English wickets fell for just 61 runs, the rot starting when overnight batsman Ian Bell was given out lbw to Harris on a third umpire eview for 15, after he was initially given the benefit of the doubt.