Ex-army officer Ollanta Humala seems certain to face former President Alan Garcia in Peru's presidential run-off, partial first-round results suggest.
Ollanta Humala, left, and Alan Garcia seem likely to go to a run-off
With just one percent of the vote left to count, Mr Humala leads with 30.7%, followed by Mr Garcia on 24.3%.
Conservative candidate Lourdes Flores is trailing by a fraction on 23.7%.
The election campaign was dominated by the rise of Mr Humala, a leftwing nationalist, but polls do not suggest he would be certain to win a runoff.
The narrow gap between the three main contenders has delayed final results from the 9 April election from being released - an excruciating wait for the candidates.
With no candidate passing 50% support, the two leading candidates will proceed to a second round, scheduled for 28 May.
'We didn't manage it'
Supporters of Ms Flores, who include much of Peru's business community, sounded a pessimistic note as the results trickled in.
"I think we didn't manage to make up the vote difference that separated us from Alan Garcia, and for that reason Alan has advanced to the second round," said Rafael Rey, a congressman in the National Unity alliance which supported Ms Flores.
The remaining two candidates both lean to the left, confirming a recent left-wing trend in elections in Latin America.
Mr Garcia presided over Peru from 1985 to 1990, during a period of hyperinflation and a bloody insurgency by Shining Path guerrillas.
But he has promised to create jobs and to divert more of the country's mineral wealth to the poor by taxing mining firms' profits.
Mr Humala first came to public attention when he led a military rebellion against the government of Alberto Fujimori in 2000.
An ally of Venezuela's Hugo Chavez, has also promised to redistribute the country's mineral wealth, and opposes a free-trade agreement with the US.
Despite Mr Humala's first-round lead, analysts predict most of Ms Flores' supporters would be likely to turn to Mr Garcia in a run-off.
A Datum poll published on Tuesday suggested Mr Garcia would win a run-off against Mr Humala, with 54% against 46%.