Independent candidate Gerard Craughwell has won the Seanad by-election, beating Fine Gael's John McNulty and Sinn Féin Councillor Catherine Seeley.
Senator Craughwell was ahead of Mr McNulty after the first round by 87 votes to 84.
Ms Seeley's 22 votes were then redistributed, with Mr Craughwell emerging victorious after receiving another 11 votes to Mr McNulty's one.
Speaking on RTÉ’s News at One, Senator Craughwell said he had expected the vote to be close given the way the election had ebbed and flowed over the past two weeks.
He said he would have to compliment the Twitter community who he said "broke" the story about the circumstances surrounding Mr McNulty's selection as the Government candidate.
He said they had given him the reason to ask the question.
The newly-elected senator accepted that he had got most of the good publicity out of the campaign.
He acknowledged the McNulty family probably suffered a lot during the campaign and said Ms Seeley had received no publicity at all.
He said it was ridiculous that it required nine TDs or senators in order to get on the nomination paper and reform was now his focus.
Senator Craughwell said the electorate for the Seanad must be looked at.
Sixteen of the 223 Oireachtas members failed to vote in the election, while there were also a number of invalid ballots and spoiled votes, meaning there were 193 valid votes.
Mr Craughwell was the only candidate present at the count in Leinster House.
Mr McNulty had asked TDs and senators not to vote for him after controversy surrounding his appointment to the board of the Irish Museum of Modern Art and his subsequent Seanad nomination.
Meanwhile, polls are now closed in the two Dáil by-elections, Dublin South-West and Roscommon-South Leitrim.
In Dublin South-West, 11 candidates are running to replace Fine Gael's Brian Hayes, who was elected to the European Parliament in May.
Ten candidates are contesting the Roscommon-South Leitrim by-election to fill the Dáil seat vacated by MEP Luke Ming Flanagan.
Turnout in both constituencies was reported to be relatively low throughout the day.