Amani National Congress chairman Kelvin Lunani has conceded defeat in the race for the Butula parliamentary seat in Busia County.
He took the decision even before the electoral commission announced the final results.
Mr Lunani, suggesting that the incumbent Joseph Oyula of ODM was ahead from his tallies, said he would work closely with the winner to improve the lives of Butula residents.
"We all come from Butula and I promise to support whoever will be elected. Oyula has won and I want to take the opportunity to congratulate him as he embarks on his second term," he said.
Constituency returning officer John Kirui said tallying was underway and they had counted results from 30 of 139 polling stations and were waiting for results from two centres to arrive.
They expected all the results to be out in 12 hours.
Two term jinx
Butula has not re-elected an MP for two consecutive terms since 1998. But Mr Oyula is poised to break this jinx, going by the provisional results.
In Teso South, UDA parliamentary candidate Mary Emase expressed confidence that she will win the elections.
She said the results she had collected from her agents across the constituency showed that she was ahead of outgoing Busia Governor Sospeter Ojaamong (ODM) and the incumbent Geoffrey Omuse (independent).