Ecuador's presidential election will go to an April run-off between leftist government candidate Lenin Moreno and ex-banker Guillermo Lasso after a nail-biter first round.
Moreno needed 40 per cent of valid votes and a 10 percentage-point difference over his nearest rival to win outright.
He was the clear leader of Sunday's election, pocketing 39.21 per cent of valid votes versus 28.34 per cent for Lasso, with 95.3 per cent of votes counted.
With the Andean country on tenterhooks and the opposition protesting for prompt results, the electoral body said the results could not change, although it was waiting for all ballots to be counted before officially proclaiming a second round.
Opposition protesters had massed in front of the electoral council headquarters in mountainous capital Quito since Sunday to denounce what they say were fraud attempts.
The government retorted they were inciting violence and urged patience.
Ecuador's fragmented opposition is now expected to close ranks around Lasso in a run-off amid anger over an economic downturn and a series of corruption scandals, potentially ending a decade of leftist rule in Ecuador.
Should Ecuador move to the right with a second-round victory for Lasso, it would follow on the heels of Argentina, Brazil and Peru, which have swerved away from the left as a China-led commodities boom ended.
Lasso has campaigned on a platform to revive the economy, which is dependent on exports of oil, flowers and shrimp, by slashing taxes, fostering foreign investment and creating a million jobs in four years.
He has also vowed to remove WikiLeaks founder Julian Assange from the Ecuadorian embassy in London and denounce Venezuela's socialist government.
