New Zealand's job today is simple: bat through it, and they'll have taken a decent step to saving the test.
And the spinoff from that could be arriving in Adelaide for the pink ball test still with a chance of squaring the series.
That prospect appeared slim after a grim day one in Perth, when Australia set up what became their fifth highest total against New Zealand.
It must have been galling for the New Zealanders to have the best of the three possible results, in their eyes, whipped away so early in the contest.
From then, it became all about ensuring they don't lose in Perth.
It was New Zealand's day at the Waca today - they took seven for 143 with smart bowling, then had a solid final session --- a first in this series
The tourists will target 360 at the first piece of business today, thus avoiding the follow on.
Golfers, think moving day - New Zealand pushing to shore up their position; Australia intent on pressing hard to take Adelaide off the table in terms of the series equation.
The first day had been all about David Warner, as he compiled the most runs in a day in a test in Australia.
In a sense, yesterday had started out all about the pugnacious Sydneysider too, but for a different reason.
When he walked out on an even hotter day than Friday - 39.4 was the temperature reading before lunch - he was 157 runs away from eclipsing Brian Lara's 400 at the world's highest test score.
There was high anticipation, but Warner yesterday was a distance away from Friday's Warner.
When he was out in the fifth over of the day, some of the air went out of Australia's tyres.
''I felt good," Warner said last night. ''They just showed us how to bowl with the new ball this morning. They adapted, knew what they had to do."
And the more so when his captain, Steve Smith followed shortly after. It was a good demonstration of the value of tight, thoughtful bowling, so different from Friday, when the marauding Warner held all the cards.
New Zealand's bowlers had some satisfaction, none more so than Mark Craig. The offspinner has had it tough, as they say in these parts.
Flogged in Brisbane, he began yesterday with none for 77 off 14 overs, ended it with three wickets, and had missed a chance to join Peter Petherick and James Franklin as New Zealand's only test hat trick takers.
Starc had greeted Williamson with a slippery bouncer and fast bowler's glare.
Williamson offered a difficult chance to Joe Burns at short leg on three off Josh Hazlewood, then clipped a ball onto Burns' helmet just after tea.
That was the ball after Australia wasted a referral on a catch at the wicket against Williamson. Daylight could be seen between the batsman's bat and front pad.
It suggested an understandable desperation to get rid of the main man. You couldn't blame them for trying.
''He's been their rock and proved it again today," Warner said.
''He gets himself in, it's a nice batting wicket and he puts away bad balls."
