The scenes at the National Party HQ in Mana electorate last night were reminiscent of the All Black test at Old Trafford in 1997.

England did a victory lap despite having been beaten 25 - 8 because they did a heck of a lot bettter against the champions than they were supposed to.

Prime Minister John Key did his own version of a victory lap last night, relishing in the result which saw National's Hekia Parata slash Labour's majority in the Mana byelection.

"I never thought coming second in politics would feel so good," he said.

"Sometimes losing is winning and this is one of them where we have had a tremendous result here."

Hekia Parata had turned Mana, the previously ninth safest Labour seat with a majority of 6155 into a marginal of seat of a 1080 majority to Labour's Kris Faafoi.

Key suggested, not unfairly, that the 14 per cent swing towards National would dent Phil Goff's leadership.

"In all probability, the swing should have gone against National because that's what happens when you are the Government campaigning in a very safe Labour seat and he has been thrashed."

"When this campaign began, Phil Goff said this byelection would be referendum on the Government's policies. Well he was right!"

Key would not comment on Parata's prospects for promotion as a minister to fill the vacancy left by Pansy Wong's resignation.

But within the party it is acknowledged that Parata's strong performance in the campaign has strengthened what was already a good reputation and high profile.

Parata's speech began in Maori paying tribute to her Ngati Porou forebears and following it, her brother Selywyn Parata and other whanau and supporters (including husband Sir Harawira Gardiner and Dame Iritana Tawhiwhirangi) brought the place alive with an action song following it.

It was quite a different National Party in Mana last night.

Several hundred National faithful crowded into The Lodge function centre at Pauatahanui to watch the results.

The mood was jubilant, not mock jubilant. And if National has had a jubilant defeat, Labour perhaps had an embarrassing victory.

Not that you would know it from the faithful gathered at the Pataka gallery in central Porirua.

It had to be remembered, they said, that Faafoi had had only a seven week campaign, whereas Parata who has stood there twice before has had a five year campaign.

And, they said, Parata's total vote from the 2008 election had fallen from 11,915 to 9317.

That is hardly suRprising given that the turnout is estimated to be about 54 per cent of enrolled voters.

Winnie Laban's vote in 2008 of 18,070 towered above Faafoi's last night of 10,397.

But the one thing neither the jubilant losers at The Lodge or the defiant victors at Pataka can argue with is the reality that Faafoi won on the day. Full credit.