Australia may have ended New Zealand's bid to reach the World Cup semi-finals off course as they beat their old rivals by 86 runs.
The Black Caps made a poor fist of chasing 244, bowled out for 157 after a Trent Boult hat-trick earlier restricted Australia to 243-9.
Usman Khawaja (88) and Alex Carey (71) were the only batsmen to settle for the defending champions, adding 107 for the sixth wicket.
But New Zealand struggled to build partnerships in reply as Australia strangled them with disciplined bowling, Mitchell Starc taking 5-26 to lift his wicket tally for the tournament to 24.
In a repeat of the 2015 final, Australia emerged victors over their Trans-Tasman neighbours once again.
But having already booked their semi-final place with victory against England on Tuesday, this win maintained momentum in their bid to retain the trophy.
New Zealand's second defeat in a row after going unbeaten for the first six games of the tournament leaves them still uncertain of reaching the knockout stage.
Their final group game comes against hosts England at Chester-le-Street on Wednesday, where both sides could need a victory to reach the last four.
Having been edged out by Pakistan last Wednesday by six wickets, this defeat may well have left a few mental and physical scars after an impressive display in the field seemed to put them on course for victory.
David Warner headed off to hospital not long after the game to join his wife Candice, who is set to give birth to their third child either later tonight or overnight.
Australia 243-9 (50 overs): Khawaja 88, Carey 71; Boult 4-51
New Zealand 157 (43.4 overs): Williamson 40; Starc 5-26
Australia win by 86 runs