Sinn Fein President Gerry Adams has topped the poll and secured election on the first count amid jubilant scenes at the constituency count centre in Louth.
His extraordinary victory in the face of strong opposition by a hostile 26-County establishment has set the tone of a significant political breakthrough by the party south of the border.
His triumph followed the poll-topping re-election on the first count of Pearse Doherty in Donegal South-West, just a number of weeks after his by-election victory began the process leading to the General Election.
Further not, another party colleague, Padraig MacLochlainn, topped the poll after the first count in Donegal North East, just two hundred votes short of a quota and well clear of his nearest Fianna Fail rival.
Elsehwere, outgoing Minister of Finance Brian Lenihan secured election in Dublin West -- and incredibly, appears set be the only Fianna Fail TD returned in the capital.
Dublin West has now completed the count process, although first counts have yet to be declared in many constituencies.
The first 27 seats of the Dublin parliament have now been filled. So far, Fine Gael has nine seats, Labour nine, there are five Independents, two for Sinn Fein and two for Fianna Fail.
Fine Gael leader Enda Kenny said it was an “historic day” for the party, which may end up with more than 75 of the 166 seats. Mr Kenny is not ruling out a single-party Government just yet, saying he wants to wait to see the final breakdown of seats.
Labour is likely to finish in second place, behind Fine Gael, for the first time in its history, and probably secure up to 40 seats. Party leader Eamon Gilmore has refused to commit his party to a deal to share power.
Sinn Fein’s Martin McGuinness has warned the Labour party not to enter coalition with Fine Gael.
The North’s Deputy First Minister, who has travelled to the Cavan count centre, warned Eamon Gilmore that if he gets into bed with Fine Gael, it will be “the biggest mistake Labour ever make”.
He added that Sinn Fein would have to be “the voice of the most under-provileged within society” following the election.
Sinn Fein continues to perform well in other parts of the country, and is battling for a number of seats in Dublin.
Dessie Ellis has finised in second position on the first count in Dublin North-West, and is all but guaranteed a seat. However, Eoin O Broin is seen as unlikely to take the fourth seat for the party in Dublin Mid-West.
In Kerry North/West Limerick, Martin Ferris has also finished second on the first count, and appears sure to hold his seat.
In another major upset, Jonathan O’Brien has topped the poll for Sinn Fein and appears likely to be elected, but remains short of a quota by some 2,500 votes.
Further results as they come in.