Jonny Bairstow said England would face a "huge morning session" on day two of the third Test after Australia got off to a flying start in Melbourne.
Armed with a 2-0 series lead and needing only a draw at the MCG to retain the Ashes, Australia bowled out England for 185 and then raced to 61-1 at stumps.
The game could yet turn, but England cannot afford to allow Australia to build a big lead, after the one-sided nature of the previous contests in Brisbane and Adelaide.
Captain Joe Root top-scored with 50 for England on Boxing Day, with Bairstow weighing in with 35, but the openers failed and tenacity was widely lacking as Australia picked up cheap wickets. Dawid Malan showed some grit but made just 14 runs, sharing in a stand of 48 with Root before becoming the third of Pat Cummins' three victims.
Root's innings gave him a ninth Test half-century in Australia, the most by a touring player in the country without having gone on to make a hundred.
Bairstow told the BBC's Test Match Special: "To lose the toss and get put in on a pitch that was doing plenty, I thought we grafted pretty well first up. Dawid and Joe put on another good partnership. We were really unfortunate to lose Dawid before lunch, otherwise that would have been a good session for us.
"We've seen there's a little more inconsistent bounce this evening. Marcus Harris got one on the glove and the following ball didn't carry through to the keeper. We'll be looking to exploit those areas in the morning; the morning session will be a huge session and let's see how we go."
Harris was left with a bleeding finger after being hit by a ball from Ben Stokes that bounced sharply. The Australia opener will resume alongside nightwatchman Nathan Lyon in the morning after James Anderson had David Warner caught for 38 by Zak Crawley shortly before the close.
Warner had been typically aggressive as he looked to compound England's misery, but a thick edge to Crawley at gully ended his assault.
"He was always looking to put pressure back on our bowlers. That's how he plays," Bairstow said. "He's scored runs in this series and previously, so it was a big boost to pick him up just before the end, and we'll come back in the morning, all guns blazing and ready to go."
Australia did not let Warner's wicket dampen their enjoyment of the day.
Captain Cummins and spinner Lyon both returned figures of 3-36, while Cameron Green and debutant Scott Boland chipped in with a wicket apiece.
Mitchell Starc removed Root and Bairstow as he took 2-54, and the paceman said on BT Sport: "It was quite a bit tacky underfoot and the spikes didn't really grab until that last session, so there was maybe not the air speed from us all today, but I thought we still bowled really well.
"We probably bowled a fraction fuller than England in that first session for them, and Pat was fantastic to get those first wickets and get us under way.
"Collectively, [bowling England out for] 185 is a pretty good day for us today."
Boland said it had been "a very special day", as the 32-year-old Melburnian made his Test bow and had a wicket – dismissing Mark Wood lbw – and two catches to show for it.
Starc was full of praise, saying: "It was awesome, the big Victorian here at his home ground to get his cap. He said he was quite nervous under a couple of those catches, but to get his first wicket at his home ground on the day of his debut was fantastic to see, and I think that might just calm him down for the second innings."