Former Guatemalan military ruler Efrain Rios Montt appears to have failed in his attempt to be elected president.
Rios Montt has overshadowed Guatemalan politics for decades
With two-thirds of the votes counted from Sunday's presidential election, he comes a distant third with 17%.
General Rios Montt was beaten by both the conservative Oscar Berger and by centre-left candidate Alvaro Colom.
As neither of the two front-runners won more than 50% of the vote, they will face each other in a run-off next month.
Sunday's election, marked by a huge turnout, was only the second presidential contest in Guatemala since peace accords in 1996 ended a 36-year civil war.
Partial results were announced by election officials, after 65% of votes had been counted.
Mr Berger, who heads the conservative Great National Alliance (Gana), got about 38% and Mr Colom 27%.
Because neither reached 50%, they are due to take part in a second round of ballot on 28 December.
General Rios Montt's candidacy was controversial because of his past as the leader of a military coup in 1982.
He got his name on the ballot despite a constitutional rule that no-one who had overthrown a government could stand for the presidency.
On Sunday, he was met with whistles and boos as he arrived to cast his vote at a polling station in Guatemala City.
The BBC's Claire Marshall in Guatemala City says people will be watching the reactions of Mr Rios Montt's supporters, and particularly the former paramilitary groups, if his first-round defeat is confirmed.
The run-up to the election was marred by incidents of violence. More than 22 people connected with political parties have been killed since campaigning began in May.
There were riots in Guatemala City in June in support of Mr Rios Montt when it looked as if he would be barred from standing.
Late on Saturday, Ronaldo Morales - a political secretary of one of the leading contenders, Mr Colom - was shot and injured by unidentified gunmen at his home.
Mr Morales' wife said the attack was politically motivated.
During Sunday's voting, two women were killed in a stampede at a polling station as a crowd rushed to cast their ballots.
People queued for hours to vote, many having travelled for hours to reach voting stations from the country's remote jungle and mountain regions.
"There were too many people who wanted to vote," said Oscar Edmundo Bolanos, president of the national electoral board.