"What an awesome night," he told the thousand strong crowd of cheering party faithful.
"I always said it would be tight, but for the next three years there will be another National party leading New Zealand.
"More people voted National today than 3 years ago and I want to thank each and everyone of you.
"Tonight New Zealanders voted for a brighter future and there will be a brighter future.
"I will continue to lead a government that serves the interests of all New Zealanders.
Mr Key said he's spoken to Maori Party co-leader Tariana Turia, and expects the Maori Party will continue to support the National government.
He capped off a short statement by thanking his campaign manager Steven Joyce, deputy leader Bill English, his press and electorate teams and lastly, his family.
He told the crowd to enjoy their night and said he was "off for something stronger than a cup of tea."
It wasn't our time - Goff
Labour's Phil Goff, told supporters at his party's headquarters in Mt Roskill 'it wasn't our time this time'.
He said he'd rung Prime Minister John Key to congratulate him.
Mr Goff celebrated the fact there were new Labour MPs entering Parliament, but said with "sadness and regret" some colleagues would not be returning.
Mr Goff said in a democracy the public decide who represent them and he respected that decision.
"It wasn't our time this time, but we are members of a great political party," he said.
"Our time will come again and we will be reader to take New Zealand forward at that time."
Mr Goff said the party's supporters can hold their heads high.
Speaking at a standup after he'd thanked his supporters, Mr Goff wouldn't be drawn on his leadership, saying it was a matter he would discuss with his caucus in the coming days.
He at least managed to hold on to his seat by more than 6000 votes over National's Jackie Blue.
John Key too, comfortably managed to hold his Helensville seat, with a 19,000 vote lead over Labour's Piers Jeremy Greenbrook-Held.
Banks takes Epsom, Brash quits leadership
In the closely watched Epsom race, Act's John Banks won by 2485 votes over National's Paul Goldsmith, securing National an important coalition option.
Act leader Don Brash thanked his party's supporters: "Despite all the commentators, all the polls, all the media, we did it. You did it, John Banks did it, the people of Epsom did it.
"I want to thank John Banks, he did a fantastic job."
However the low result has seen Dr Brash resign.
He said he'll hand his resignation to the Act Board after it became clear that he would not get back into Parliament.
Close races
There were some close races tonight, none more so than Christchurch Central - which was left somewhat unbelievably in a tie.
Labour's Brendon Burns and National's Nicky Wagner are in a dead heat.
Special votes there will be crucial in deciding the outcome, as they may in other tight races.
In Auckland Central National's Nikki Kaye has a 535 majority over Labour's Jacinda Ardern, and National's Kate Wilkinson has a 395 vote lead over Labour's Clayton Cosgrove in Waimakariri.
National's Paula Bennett holds her Waitakere seat by just 349 votes over Labour's Carmel Sepuloni.
Carmel Sepuloni's supporters have praised her and cheered her on saying the fight is not over yet.
Ms Sepuloni said: "I don't want anyone in this room to feel sad in anyway at all because we fought a very hard fight."
"We are not going to concede yet because there are over 3000 special votes that have not yet been counted in this electorate".
Maori Party co-leader Pita Sharples has a 742 vote lead over Labour's Shane Jones in Tamaki Makaurau, and Mana's Hone Harawira has a 799 lead over Labour's Kelvin Davis in Te Tai Tokerau.
Low night for Labour
A former Labour party president described the result as an "unmitigated disaster."
Mike Williams, has spoken out over the low polling of the party in the 2011 election.
He said that the 27 per cent party vote for Labour - among its lowest polling results ever - is a disaster for the party.
Among the casualties are a range of Labour stalwarts including Stuart Nash, the Labour candidate in Napier, an icon of the party whose grandfather was the great Walter Nash, Labour PM after World War 2.
"This is a terrible night for Labour," said Williams.
Meanwhile Labour candidate David Parker has refused to say if he will back Phil Goff staying on as leader after the election, but said he will not be demanding his resignation and was "bloody proud" of Mr Goff for the campaign he had run.
"Tonight's not the night for that. I want to reflect on what's happened and I want to give Phil the dignity he deserves."
He said it was up to Mr Goff whether he resigned or not "but I certainly won't be demanding it."
Referendum - MMP favoured
With 100 per cent of the 284,312 advance votes counted in the referendum, 53.89 per cent of voters were keen for MMP to be retained, while 42.46 per cent would like the system change, and 3.65 per cent were informal.
Asked which system voters would prefer should MMP be abandoned, 31.76 per cent opted for First Past the Post, 14.48 per cent chose Supplementary Member, 11.27 per cent picked Single Transferable Vote and 8.21 per cent chose Preferential Vote, while a whopping 34.29 per cent cast informal votes.
'Voting went well' - Electoral Commission
Voting around the country was reported to have gone smoothly despite the windy conditions, particularly in the North Island.
The Electoral Commission said late in the afternoon that voting at polling places around the country had gone well.
An incident at an Auckland polling station in Mt Roskill at 3pm had to be defused by police, after a voter abused returning officers.
The man was angry at the layout of the voting forms.
Police managed to calm the upset man down and allowed him to vote before removing him from the school.
In the capital, a man aged in his 60s was rushed to Wellington Hospital after collapsing at a polling station.
He's in intensive care at Wellington hospital in a critical condition.
