Colombia is set for a run-off vote after former defence minister Juan Manuel Santos fell just short of victory in Sunday's presidential poll.
Mr Santos, a close ally of President Alvaro Uribe, took nearly 47%, with his nearest main rival, Antanas Mockus of the Green Party, trailing on 21%.
Mr Santos is likely to get the support of some of the defeated candidates in the second round on 20 June.
He has promised to continue Mr Uribe's tough security policies.
Mr Mockus, a former mayor of Bogota, has put more emphasis on education and fighting corruption.
Quality of life
The size of Mr Santos's first-round victory came as a a surprise, as many opinion polls had placed the two main contenders neck and neck.
The BBC's Jeremy McDermott in Colombia says the result is effectively a vote for a continuation of the security policy that has been the hallmark of the two administrations of Mr Uribe.
Reacting to the announcement, Mr Santos said: "This is your victory, President Uribe, and for all of us who want to defend your enormous legacy."
Mr Uribe still has approval ratings of 60% after almost eight years in power. He is credited with policies that have curbed guerrilla activities and reduced drugs crime.
Mr Mockus, for his part, told supporters: "Today we've reached a goal that seemed impossible a few months ago: going ahead to a second round. If we're creative, we'll win that second round."
Mr Mockus is seen as having improved the quality of life for citizens in the capital with public works projects during his two terms as mayor.
His supporters point to his economic record, while his critics say he is too inexperienced to run the country, in particular in maintaining the pressure on the left-wing rebels.
For the first round, the main parties that formed Mr Uribe's governing coalition, the Conservatives, Cambio Radical and Mr Santos's Partido de la U, all fielded their own candidates.
Speaking after the first round, Mr Santos appealed to them to back him.
"I am calling for national unity without making a distinction between political parties and personalities," he said.
German Vargas Lleras, who looks set to win third place, has already hinted that he will back Mr Santos, effectively delivering him another 10% of the electorate.
The Conservative Party gained another 6% of the vote, which is also likely to go to Mr Santos, analysts say.
Voting passed off largely peacefully, although four soldiers were killed in clashes with Farc rebels in the southern department of Caqueta.