Needs must. After flirting with some adventure mixed with arrowhead forward drives, the All Blacks pooled all their resources into pragmatic test rugby.
Bingo. The Bledisloe Cup was saved, the Tri-Nations claimed, all was well at a soggy Eden Park after the All Blacks' 26-12 victory against their transtasman rivals.
It was Rugby 101, the sort of fundamental footy needed in conditions that provided a massive test of the players' temperament, attitude and patience.
For parts of the opening spell the All Blacks were a shade skittery as their attacking instincts battled with the demands for core rugby.
They tried too many deep lineout throws and were picked off four times by the Wallabies, they did not have one feed to a scrum as the visitors displayed an extraordinary level of handling security, but the All Blacks still hankered for enterprise as a way of finding victory.
It brought disconcerting thoughts about a midweek address from coach Graham Henry in which he pondered the style of rugby needed to win the World Cup and how the All Blacks would not be deterred from using their attacking skills - it was not in their psyche.
On a soggy Auckland Saturday, it had to be. The All Blacks had to alter their mindset, they had to change their ideas if they were to defend the silverware. "We try to play to our strengths and the way the guys enjoy playing," Henry said before the test.
"If you played a game that was dry and kicked the ball in the air, chased it and dropped goals, I would think we would be a very poor side."
Henry must have changed that prescription on Saturday as rain throughout the day and the thunderstorms that descended on the ground just before kickoff dictated a much lower-risk style for both sides. The All Blacks showed flashes of it throughout the first half but they were forced into a great deal of defensive work.
Into the dressing rooms and there were stern words from the coach, as five-eighths Daniel Carter revealed.
Lineout throws went towards the front while hooker Keven Mealamu also added some sting, Carter was able to build the pressure with his gifted left boot, replacement Brendon Leonard ramped up the tempo and the momentum of the test changed.
The 12-9 halftime lead was stretched out to 18-12 and when the video ref apparently found some evidence Tony Woodcock had grounded the ball across the line, the All Blacks were safe. "We are reasonably satisfied where we are at," captain Richie McCaw said.
It had been pragmatic rugby, sensible rugby. The sort that, come the World Cup, may be needed in equally difficult conditions. It was an invaluable final domestic hit-out, a victory under all sorts of pressure in a season punctuated by the growing shadow of World Cup preparations.
"We built the game better as it went on," Henry acknowledged.
"We got the ball in front of us, our lineout improved - which was the key - we had dominance at scrum time and we did not try to go too lateral."
Wallaby coach John Connolly accepted his side got the better of decisions at the McG, when they won, and on Saturday lamented three judgments from rookie referee Nigel Owens that went against his team.
He disputed penalties against his captain Stirling Mortlock for a marginal high shot and against fullback Adam Ashley-Cooper for throwing the ball away, and Woodcock's try.
"It just changed things and I don't think there is a lot between these two teams. These games have been so tight that the difference can be just the little things," he said.
While the Wallabies had much of the possession in the first half they did not look like breaking the All Black defence, where Doug Howlett was swamped with bombs but held firm and the midfield clamped tighter than duck feathers during a hailstorm.
In contrast, the All Blacks, even as they simplified their attack lines close to their pack, put the visitors' defence under much more heat.
Carter was back towards his lordly best; his tactical kicking in length and accuracy was much superior to anything Stephen Larkham or Matt Giteau could offer. It was a point Connolly accepted and has tried to address by using league legend Andrew Johns at training camps.
It was a tough test for all, including the pre-match entertainers and the capacity crowd. It was a home-soil farewell for Anton Oliver and possibly Chris Jack, Carl Hayman, Byron Kelleher and Aaron Mauger, who are heading overseas.