Governing party candidate Juan Manuel Santos has won the final round of Colombia's presidential elections.
With almost all the votes counted, Mr Santos had won 69% of the ballots and was more than 40 points ahead of his rival - Green Party candidate Antanas Mockus.
Mr Santos shares outgoing President Alvaro Uribe's tough line on security.
In his victory speech, he told the country's main rebel group, Farc, that its "time had run out".
He said there would not be "the slightest chance of negotiations" with the rebels and demanded they unilaterally release the hostages they hold.
Last week, the Colombian security forces rescued three police officers and a soldier who had been held captive by Farc (Revolutionary Armed Forces of Colombia) for almost 12 years.
Mr Santos, a former defence minister, praised the country's armed forces for the rescue, as well as their day-to-day work to keep Colombians safe.
He said he would not rest until they had secured every inch of the country.
But in a week when two soldiers were sentenced to 28 years in prison for carrying out extrajudicial killings, he warned the military to abide by the constitution and respect human rights.
Mr Santos also praised his predecessor Alvaro Uribe, for whose Social National Unity Party he ran.
Even after eight years in office, Mr Uribe's approval ratings remain as high as 60%, and Mr Santos said he was keen to build on his success.
"This is your triumph, too, President Uribe," he said. "We'll build on the progress you achieved over the past eight years.
"Thanks to the security we've created, we can now focus on creating jobs, fighting poverty and providing opportunities for all Colombians," he promised.
Election day deaths
But Mr Santos also reached out to his defeated rival, Antanas Mockus, saying that if in the heat of the campaign some blows had been traded, now was the time to heal those wounds.
He said the time had come for national unity and invited all Colombians, not only those who had supported him, to "fly the banner for a united, educated and just Colombia".
Earlier, Antanas Mockus congratulated Mr Santos on his win.
He said Colombians could continue to count on the Green Party to turn Colombian politics into something its citizens could be proud of.
One of his campaign promises had been to put an end to the corruption scandals that swirled around the Uribe government.
Mr Mockus told his supporters he would not let them down.
He also gave his condolences to the families of 10 members of the security forces killed on election day.
Seven police died in the north-east of the country in an ambush blamed on left-wing ELN rebels.
And three soldiers were killed in battles with Colombia's main rebel group, the Farc.
But correspondents say the level of violence was much lower than in previous presidential elections, when Colombia's rebel groups managed to seriously disrupt voting with attacks across the country.