Kitui gubernatorial candidate David Musila on Thursday telephoned former Cabinet secretary Charity Ngilu to concede an early defeat.
And in a press statement, Mr Musila said he had accepted the outcome and offered to support Mrs Ngilu, the governor elect, by rallying his supporters in healing and taking the county forward.
Mr Musila thanked Kitui voters for turning up in large numbers.
"I thank the more than 108,000 people who voted for me.
"However, those votes did not translate to victory and I therefore concede defeat and ask the people of Kitui to support the Governor elect Hon Charity Kaluki Ngilu," the statement read.
Mr Musila advised the other candidate and incumbent Julius Malombe of Wiper party to also do the same.
"Dr Malombe should do likewise by accepting the results to allow the people to heal and move on."
However, Dr Malombe rejected the results alleging he had been rigged out and that there were malpractices.
Provisional results from 95 per cent of the polling stations indicate that Mrs Ngilu, the NARC flag-bearer, has 163,763 votes, Mr Musila (independent) has 109,793 votes and Dr Malombe has 72,182 votes.