The Ulster Unionists have lost the South Belfast seat to Alasdair McDonnell of the SDLP.
Alasdair McDonnell said he would represent everyone in South Belfast
Mr McDonnell took 10,339 votes and the DUP's Jimmy Spratt was second with 9,104.
Ulster Unionist candidate Michael McGimpsey trailed in third place with 7,263 votes.
The split unionist vote gave the seat to a nationalist politician for the first time. The defeat is a major upset for the UUP.
Mr McDonnell said people in South Belfast had "sent a loud and clear message that tribal politics is not the only way forward in Northern Ireland".
"We (the SDLP) are still standing strong and we are ready to fight back for the values that the people out on the streets and doorsteps want," he added.
The DUP's MEP, Jim Allister, blamed the nationalist win on David Trimble's party and what he said was its refusal to agree an electoral pact.
"The responsibility lies at the door of the UUP," he said.
Mr Spratt said of his vote: "The seat belonged to the people and I think the people have responded loud and clear right across the province in their support for the DUP.
"They want to see unionism uniting."