The Black Caps looked in a strong position early in the game with Boult and Ferguson reducing Australia to 92 for 5 at Lord's on Saturday.
London: Skipper Kane Williamson emphasised on competing with the right mindset, which allows to play with freedom after New Zealand slipped to their second defeat in the World Cup.
The Black Caps looked in a strong position early in the game with Trent Boult and Lockie Ferguson reducing Australia to 92 for 5 at Lord's on Saturday.
But a 107-run partnership for the sixth wicket between Alex Carey (71) and Usman Khawaja (88) changed the course of the game as Australia battled to 243 for nine.
It proved to be a stiff target as New Zealand fell to 157 all out in their chase.
"Once again, it is about moving on, and going to Durham and looking forward to a new surface and new opposition (England)," Williamson said after the defeat.
"We as a side need to be really positive and play with that freedom, because when we do that, that is when we play our best cricket, and that's the sort of mindset we need to have."
New Zealand, who are currently placed third on points table, had suffered their maiden defeat of the tournament at the hands of Pakistan delaying their qualification for the knockout stage.
However, if India beat hosts England, it could see New Zealand into the semi-finals. Failing that, the Black Caps may have to beat the hosts in their final group game in Durham to secure a spot in the last four.
"Maybe there's a dent in momentum. But then at the end of the day, it is coming back to the cricket that we want to play. Playing with those cricket smarts throughout this tournament has been perhaps the most important thing."
Talking about the loss to Australia, Williamson said the partnership between Carey and Khawaja bolstered Australia to a competitive total.
"I think that partnership between Khawaja and Carey was superb. I don't think anybody hit the ball well on that surface all day except for Carey, and they managed to put on 100, which certainly got them a very, very competitive total.
"I suppose we were one wicket away if you're looking at positives in terms of our bowling performance and trying to restrict them to a much lower total, but it wasn't to be. The match-ups didn't really fall our way with both our spinners turning the ball in to two left-hand batters," Williamson said.