The early losses of Warner and Steve Smith yesterday certainly helped.
Chalk the relatively quiet morning up to Southee, an improved Trent Boult, Matt Henry and Doug Bracewell.
The thought occurred that New Zealand haven't suddenly become a hopeless side in the space of a few days.
They had no chance at Brisbane on two counts; they were badly underdone; and they lost the toss and chased leather for a day and a half.
In Perth, the toss went Australia's way again on a runway of a pitch and Warner was flying from Boult's first over.
''Schedules at the moment reflect nothing so faithfully as the short-termism and self-interest that has enveloped the cricket world in the past decade," wrote leading writer Gideon Haigh in The Australian yesterday.
Take away Kane Williamson's dazzling century in Brisbane, and yesterday's work -- from the bowlers then Williamson and Ross Taylor -- was the first time in the series New Zealand players, collectively, were competing on an even keel. Leave aside the scoreboard; in actual ball by ball work it was tidy.
''It's a nice batting track," Bracewell said last night. ''Kane and Ross showed that tonight. A couple of cracks are starting to appear but we're looking to bat time."
New Zealand are justly proud of their recent record, unbeaten in seven straight test series. By digging deep over the next three days they can go to Adelaide and the pink ball decider still with hopes of squaring the series.
After what's happened so far, that would be terrific outcome.
Then New Zealand get the chance to have another go at Australia in their own conditions in February.
Expect that to be an intriguing contest. Should things go badly wrong in the next eight days of test cricket, that argument still holds up. Different place, pitch conditions and vibe.
New Zealand have not suddenly become poor. They have played some poor cricket, and there is a distinction.
The first two days have also included frequent ball changes. By stumps there have been five replacement balls needed, outside the three for standard reasons.
''I'm not sure what to put that down to, it's a hard wicket, they seem to get soft pretty quickly these days," Bracewell said.
Australia will likely need a new No 3 batsman for Adelaide, after Usman Khawaja pulled his left hamstring late in the afternoon.
