Fiji were expected to struggle in a tight contest against supposed top drawer opposition having averaged 56 points in three big pool victories over minnow sides USA, Wales and Italy, but it was the Kiwis who lacked composure and intensity despite the importance of the occasion.
Questions now hang over under fire coach David Kidwell's future with the Kiwis suffering seven defeats in 10 starts since he was appointed last September and the New Zealand Rugby league set to review his position once his current contract ends in January.
Kidwell's selections will also come under scrutiny with recalled five-eighth Te Maire Martin looking uncertain alongside halfback Johnson and the pair kicking poorly and unable to assert themselves behind a forward pack that struggled to gain ground.
Fiji enjoyed a strong start with hard running and a willingness to offload troubling the Kiwis defence with a string of errors and penalties allowing the visitors to dominate territory and possession.
The Kiwis looked vulnerable early on with Fijian back-rower Brayden Wiliame losing the ball over the try line before Koroisau kicked his side in front after 13 minutes.
New Zealand were unable to get any momentum with the ball and had racked up 106 tackles in the first quarter alone, but scrambling defence allowed them to hang on with Fijian wing Marcelo Montoya pushed into touch close to the line.
The Kiwis suffered a blow with hardworking back-rower Joseph Tapine departing with a knee injury in the 23rd minute before returning in the second half, while Fiji continued to threaten with centre Akuila Uate tackled short and captain Kevin Naiqama called back for a forward pass.
The Kiwis continued to hurt themselves in the second-half with more unforced errors and poor option-taking stifling their attack, while they were forced to cling on grimly while wing Jordan Rapana spent 10 minutes in the sinbin for a professional foul.
Fiji's attack lacked polish and they failed to find a way through the Kiwis defence but Milne put them ahead on the scoreboard and desperate defence prevented New Zealand from snatching the result at the death.