England's dismal start to the Ashes series was compounded by Travis Head's blistering century on day two of the first Test at the Gabba.
Left-hander Head tucked into a weary attack to reach three figures from only 85 balls, the third-fastest hundred in Ashes history.
David Warner, bowled off a Ben Stokes no-ball and dropped by Rory Burns, earlier made 94 and Marnus Labuschagne 74, yet when Ollie Robinson took two wickets in two balls Australia were five wickets down and just 48 ahead.
Head, though, crashed 12 fours and two sixes in his 112 not out to take Australia to 343-7, 196 ahead after England were dismissed for 147 on day one.
England's three frontline seamers carried a threat for most of the day, but left-arm spinner Jack Leach was targeted for some brutal treatment, conceding 95 runs from 11 overs, including five sixes.
Stokes looked to injure his knee chasing the ball in the field and barely bowled after lunch, while Robinson struggled with cramp late on.
There was also a worrying moment when Head was struck by a rapid accidental beamer from Mark Wood. The batter recovered and the bowler was swift to apologise.
After only two days, England are facing the prospect of going 1-0 down, and know they will have to better their first-innings effort just to make Australia bat again.
England's problems laid bare
Missed chances and the ineffectiveness of Leach aside, England could do little more on a second day that exposed the inadequacy of their performance and decisions on day one.
Whereas England opted to bat in ideal conditions for bowling, Australia's batters enjoyed clear skies on a scorching hot day.
When a team is bowled out for 147, it seems churlish to rake over bowling selections, but the way Leach was singled out raises further questions over the exclusion of Stuart Broad and James Anderson, and leaves doubts over the part he could play in the remainder of the series.
Robinson was superb, Wood bowled with extreme pace and Chris Woakes often beat the bat. However, the sight of Stokes limping is a huge concern and his nine overs cost 50 runs.
When Robinson had Warner caught at mid-off and followed up by bowling Cameron Green, who offered no shot, the game was in the balance.
Then came Head's stunning assault, which will surely extend England's 35-year winless run at the Gabba.
Head proves his worth
Head was vying with Usman Khawaja for the final spot in the Australian batting line-up and justified his selection with a memorable century.
He was at the other end for Robinson's double strike and was fortunate to survive an edge off the same bowler that flew wide of the slip cordon when he had only one.
From there, he flayed the England bowlers, cutting the pacemen and taking a six apiece from Leach and Joe Root's off-spin.
Head reached 50 from 51 balls and needed just 34 more to reach his third Test century - only Australia's Adam Gilchrist and England's Gilbert Jessop have made faster Ashes hundreds.
As the light faded he was felled by Wood, the ball thudding into Head's glove, then chin. The fast bowler showed his concern and seemed shaken afterwards.
Head, though, remains, and his presence could see Australia make rapid progress on the third morning before looking to skittle England once more.
While Broad is away, Warner plays
Warner managed only 95 runs in the entire 2019 series, when he was dismissed seven times by Broad.
But with Broad bowling in the nets rather than the middle, Warner rode his luck to get within one run of matching his tally from two years ago.
He was discomforted by the pace of Wood, bowled by the Stokes no-ball on 17, and reprieved on 48 when Burns put down a simple chance at second slip off Robinson's bowling. Warner also survived a bizarre run-out chance on 60, scrambling on all fours to make his ground as Haseeb Hameed missed with a shy from short leg.
In between he punched through the covers, launched Leach for two straight sixes and hurried between the wickets.
Warner added 156 with Labuschagne, who came through a verbal joust with Robinson to also score through the cover region and take Leach for two maximums of his own.
It was Labuschagne's eagerness to get after Leach that caused his downfall, with a miscue to point sparking England's mini-revival before Head took charge.
'Australia have been incredibly ruthless'
BBC cricket correspondent Jonathan Agnew: "People will moan at that score but I have to say I am full of admiration for Woakes, Robinson and Wood. Those three really dug deep today."
Former England spinner Phil Tufnell on TMS: "It is one of those days as a bowling unit where you sit down and think 'crikey, where did that get away from us?'. They weren't helped in the field."
Ex-England fast bowler Steven Finn: "I have no doubt Jack Leach is still the right man to be England's spinner on this trip but Australia have just been incredibly ruthless today.
"They had their foot on England's throat and they took it off for a little half an hour period, but as soon as they had the opportunity to put it back on they have. They've executed their game plan. They'll have spoken about not letting the three seamers have a rest."
England pace bowler Ollie Robinson: "It came out well today. I was consistent and had a lot of plays and misses. I sort of felt like I was going to get Warner out every over. He left well at times but there were times when I thought he was going to nick it."
Australia opener David Warner: "They bowled well and they were relentless - they hit that back of the length target all day. What an entertaining innings from Travis Head though - it was great to watch."
