Ms Avril Doyle of Fine Gael and Mr Liam Aylward of Fianna Fáil have won the two remaining European Parliament seats in the East constituency.
Shortly after midnight, Fianna Fáil's Mr Seamus Kirk was eliminated on the seventh count, leaving Ms Doyle with a lead of 6,300 votes over Mr Peter Cassells of Labour. She was elected without reaching the quota.
In the North West constituency, Fine Gael's Mr Jim Higgins held off a strong challenge from Sinn Féin's Mr Pearse Doherty to take the final seat.
At the end of the European election count, Fianna Fáil has four seats, Fine Gael has five seats, Labour and Sinn Féin one seat, and two independent seats in Ms Kathy Sinnott and Ms Marian Harkin.
The result in the East is a spectacular coup for Fine Gael and caps a successful election for the party.
Ms Doyle said: "We have to keep up the momentum. We have to work to try to make potential TDs." She added: "For me personally it was the icing on the cake to take a second seat in a three-seater."
Her running mate, Ms Mairead McGuinness, who was also elected said: "My objective was to take a second seat for Fine Gael. I always thought it was a possibility."
The continuous long count began at 10a.m. yesterday after a first round on Sunday night.
A possible factor behind the lengthy count could have been the large field of 13 candidates for a constituency whose representation has been cut from four MEPs to three.