Ireland's two traditional political rivals are being forced to mull over the prospect of an historic pact after voters handed the outgoing coalition a hammering.
With counting of two million votes under way, the election is set to throw up the most diverse Dail parliament since the foundation of the state more than 90 years ago.
The outgoing Fine Gael/Labour partnership suffered huge losses, exit polls showed.
And as Fianna Fail recovers ground lost five years ago after leading the Republic into economic collapse, the revival could bring the curtain down on decades-old rivalries with Fine Gael.
Before the first ballot boxes were opened, bookies predicted the civil war adversaries would strike a deal in time for the 1916 Easter Rising centenary.
According to surveys of people leaving polling stations by pollsters Ipsos MRBI for the Irish Times and by Behaviour and Attitudes for state broadcaster RTE, Sinn Fein, Independents, smaller parties and newcomers are all likely to make significant gains.
The first exit poll showed Fine Gael on 26.1% of first preference votes; Labour on 7.8%; Fianna Fail on 22.9%; Sinn Fein on 14.9%; Anti Austerity Alliance/People Before Profit on 3.6%; Greens on 3.5%; Social Democrats on 2.8%; Renua on 2.6%; and others on 16.1%.
RTE's showed Fine Gael on 24.8% of first preference votes; Labour on 7.1%; Fianna Fail on 21.1%; Sinn Fein on 16%; Anti Austerity Alliance/People Before Profit on 4.7%; Greens on 3.6%; Social Democrats on 3.7%; Renua on 2.4%; Independents on 11%; and the formal Independent Alliance on 3%.
The results will ask serious questions of Fine Gael leader and outgoing Taoiseach Enda Kenny over how he blew such goodwill after the party's best ever election in 2011.
Labour leader and outgoing Tanaiste Joan Burton first has the massive hurdle of retaining her seat before questions will turn to her leadership and choices in government.
However, the figures come with a health warning, given Ireland's unusual and complex single transferable vote system.
They point to a hung parliament, with the voter schism threatening to blow apart a duopoly enjoyed for more than 80 years by Fine Gael and Fianna Fail, which swapped power for generations.
There is also the prospect of a minority government taking power but seasoned commentators have warned about the instability of such a loose pact.
That option or a more groundbreaking deal putting Fine Gael and Fianna Fail on the government benches with a rotating taoiseach could also open the first definitive right/left divide in the Dail.
A less likely scenario is a rainbow coalition of Fine Gael, Labour and some smaller parties but looking at the numbers, it would take a hotchpotch of political ideologies in order to reach the magic working majority of around 80 seats.
More than 550 candidates fought in 40 constituencies to become one of just 158 TDs - eight seats fewer than the 2011 election when Fine Gael and Labour took office promising a democratic revolution.
Once a clear picture emerges from the weekend counting of votes, the parties will have until March 10 - when the Dail is scheduled to resume - to forge a power-sharing deal.
The spectre of a second election will loom over any uncertainty.
As polling stations closed at 10pm on Friday, political parties were estimating around two thirds of the 3.3 million-strong electorate voted.