Among the supporters at the party were Auckland couple Sarah Turner, 25, with fiance, Jeremy Wiklund, 23, who will marry in six weeks' time.
"This is wonderful. It's the best night of my life - until I get married of course." She said she was delighted with Key's performance. "In the middle of the financial crisis New Zealand needs to be run like a business and he's just the man for the job."
Darius Karani, 42, of Botany, joined National when he moved here from India three years ago. He said he also wanted Key to run the country like a business. "We've got amazing products in this country, but we're only selling them to four million people. We could be selling them to four billion people."
Canterbury became a battleground between National women and Labour men, as National's Kate Wilkinson won Waimakiriri from Labour MP Clayton Cosgrove by 395 votes. Christchuch Central finished the night in a dead heat between National's Nicky Wagner and Labour MP Brendon Burns, before special votes were counted.
Earthquake minister Gerry Brownlee acknowledged the benefit hard work on the quake had on the polls. "I think the recovery is going at a much faster pace than the politicians expected."
The victory will set the stage for Key to assert his dominance over a party which has long fought a city-versus-provincial divide. He and deputy Bill English work well together but come from different support bases.
Key lives in Auckland while deputy and former party leader Bill English has a rural seat in Southland's Dipton.
Young up-and-comers jockeying for position will reflect lobbying by English and Key's respective support bases. In the north, with Key's backing, is Tauranga's Simon Bridges, Auckland central's Nikki Kaye and Sam Lotu-Iiga from suburban Maungakiekie.
English is supporting the promotion of Canterbury's Amy Adams and Michael Woodhouse from Dunedin.
Also expected to be promoted was Wellington's Hekia Parata with Education Minister Anne Tolley a likely casualty of the renewal plans.
National insider Matthew Hooton said: "What we'll see in the next few days is whether Mr Key or Mr English is in the ascendancy."
Economic storm clouds on the international horizon look likely to offer Key's second term a tumultuous ride.
The danger is outlined in the Pre-election Economic and Fiscal Update, which warned of difficult times ahead if Europe failed to fix its economic problems. Since then, Greece and Italy's finances have imploded.
The Prefu Treasury forecast of "risks" outlined a fall in trade has been largely ignored during the campaign but predicted problems in Europe could create a "sharp drop" of income for farmers and less money in the New Zealand economy.
Economist Gareth Morgan said Kiwis had been largely insulated from the global economic crisis.
He said it was likely the worst was yet to come.
The money gained from the much-vaunted asset sales could instead be used to pay off debt and cushion the impact. A new downturn was likely to impact on the prices. "They're pretty committed so they have to do something."
Key launched the campaign saying: "No one owes New Zealand a living - we have to earn it." He signalled trade and the economy as critical weapons in a National Party-led defence of New Zealand's standard of living. The solution was to have "an economy where we sell more of what the world wants to buy".
Trade minister Tim Groser said the country was well-placed to weather the storm.
"If the forecast turns out to be ludicrously optimistic, yeah, we are going to have to hunker down. We are just not earning enough money to pay for the standard of living New Zealanders want. We do have to create wealth to pay for it all."
