New Zealanders' enthusiastic backing of teams other than the All Blacks has given the tournament an ideal start, say organisers and international media.
Attendances have soared as fans become caught up in the tournament's festival atmosphere, and tickets sales are set to exceed the 1.3 million target.
Tournament boss Martin Snedden, who has been to eight matches, said the World Cup could not be better placed halfway through pool matches.
The chaotic arrival of the Tongan team - when thousands of fans crowded into Auckland Airport - had created a "snowball effect" in terms of atmosphere, he said.
It was crucial that New Zealanders embraced all of the teams and matches, not just those featuring the All Blacks.
Ireland's upset victory over Australia at Eden Park on Saturday had been seen by almost 60,000 fans - about 45,000 of whom were Kiwis.
"And they chose a team - most of them Ireland - and became vocal. We saw a sea of green and gold, and flags everywhere," Mr Snedden said.
"We'll have 60,000 at Eden Park to watch Fiji versus Samoa on a Sunday afternoon. That's a good indication of where people's heads are at."
Feedback from teams and organisers had been unanimously positive about the way locals had supported and hosted them, especially in the smaller centres.
Mr Snedden said monitoring of the 200 to 300 articles published on the World Cup each day revealed most were positive about the atmosphere and fan experience at the tournament.
Robert Kitson of British newspaper the Guardian said in a column that local support of neutral games meant the tournament was on track to be a "roaring success".
"[The tournament's] place in the pantheon will be determined by games like Argentina v Romania in Invercargill last Saturday. Over 12,000 people turned up, more than 6000 of them supporting the Pumas," Kitson wrote.
"Southland has never seen anything quite like it and the atmosphere was magnificent. The staff at Rugby Park could not have been friendlier and the whole occasion was a joy."
The verdict from the Economist magazine was that New Zealand had lived up to claims that it was a "stadium of four million".
Even Stephen Jones, rugby writer for British newspaper the Sunday Times and infamous for his anti-All Blacks sentiment, admitted it had been a "terrific start".
South African Deputy Minister of Sport and Recreation Gert Oosthuizen said the tournament would deepen ties with New Zealand.
"There are thousands of South Africans in New Zealand who have come to support their team in the RWC," he said. "The atmosphere is great. They are having a good time in the normal hustle and bustle that accompanies the tournament."