New Zealand netball legend Lois Muir believes the Diamonds crumbled when tasked with coming from behind in the World Cup final because it was a new concept to them.
In assessing the Silver Ferns' shock 52-51 triumph in Liverpool, Muir said Australia has paid the price for an "open slather" approach to allowing imports into their Super Netball domestic league.
Regarded as New Zealand's greatest coach, Muir wasn't completely surprised when Noeline Taurua's team broke a 16-year drought by toppling the No.1 ranked Diamonds, who were heavily favoured to bag a 12th world crown.
She said resilience built on years of Kiwi "suffering" was the difference.
While New Zealand boasted four Test centurions - Laura Langman, Maria Folau, Casey Kopua and Katrina Rore - Australia went into the tournament with only captain Caitlin Bassett having exceeded 50 caps.
Bassett's team, so used to dominating, looked lost when New Zealand opened up a gap.
"Australia, really, has never had to fight as hard as us," Muir told AAP.
"They don't handle it as well when they have to come from behind because they haven't done a lot of it.
"That's what the crux of that final was and those older, experienced New Zealand players had control of that game."
Muir said New Zealand has ultimately benefited from the dissolution of the former trans-Tasman league in 2016.
While there was an impression Super Netball was stronger than New Zealand's competition Muir wasn't as convinced.
She believed the Kiwi league serves its country better as it is primarily a development league for players.
Australia's is commercially driven and has opened the door to unlimited imports in each team.
Diamonds coach Lisa Alexander has repeatedly criticised the lack of restriction, believing the league is actually more beneficial to other nations.
Muir said New Zealand had it right by allowing just one import per team while more than a quarter of the 80 contracted Super Netball players are from abroad.
"We've changed tack and we're managing it to our own advantage. Young New Zealand players have the opportunity to get court time and get that suffering," Muir said.
"The Australian league is just open slather."
Muir coached New Zealand for 15 years and oversaw two world title winning campaigns, in 1979 (joint winners) and 1987.