Labour has pulled Te Tai Tonga out from under the Maori party, with Rino Tirikatene winning the electorate by 1445 votes.
The electorate had been a Labour stronghold from 1999-2005, but was taken by Rahui Katene in a close-fought battle in 2008.
The large Maori electorate covers much of Wellington and all of the South Island.
The candidates battled in electorate debates earlier this month over the needs of their constituents, with many polls pointing towards the electorate's current MP Rahui Katene, of the Maori Party, retaining the seat.
Speaking from the Labour party celebrations at the Basin Reserve earlier today, Mr Tirikatene said the nerves were yet to set in.
"I have surprised myself by staying pretty calm today. I have been quite relaxed all day and not that wound up by anything.
"It is nice to be holding a lead at this stage but there is still a long way to go yet."
The nerves would not be coming until later in the evening, Mr Tirikatene said.
"I'm sure I'll be getting some jitters if the votes get closer again, but I'm trying to keep cool.
"It will be interesting to see the swing towards Labour in this electorate. I've very proud of the campaign we've run."
Maori Party co-leader Pita Sharples may also face difficulties tonight, holding only a slim majority over Labour's Shane Jones in his electorate of Tamaki Makaurau.
Labour has cemented its lead in Ikaroa-Rawhiti with Parekura Horomia commanding a 3000 vote lead over closest competitor, Maori's Na Raihania.
Meanwhile Tariana Turia is holding on to Te Tai Hauauru with ease.
- The Dominion Post