The apparently decisive outcome of Wednesday's polls could raise hopes of a new era of peace and stability in Asia's youngest nation, a year after deadly violence brought down the government and drove more than 155,000 from their homes.
"I am ready to be president now, and I will make good on promises to resolve the crisis and refugee problem," Ramos-Horta said Thursday, declining to declare victory until final results are released, expected on Friday.
Election commission spokeswoman Maria Sarmento said Ramos-Horta had won about 73 percent of the votes, with almost 90 percent of ballots counted. Authorities earlier estimated that around 80 percent of the 524,000 registered voters had voted.
Francisco "Lu-Olo" Guterres, the head of the country's largest party, Fretilin, was the only other candidate in the election. He was due to address the media Friday morning.
Voting was peaceful and free of intimidation, said Atul Khare, the U.N. special representative in the country, which won independence from Indonesia in 1999 following a referendum organized by the world body.
Ramos-Horta, who is currently the acting prime minister, has pledged to make it easier for foreign investors to do business in the country, and said U.N. and international troops currently maintained security there would be welcome to stay in the country for many years.
"I will work closely with the international community, especially the United Nations to bring this nation to a bright future," he said. "I will accelerate economic development ... to eradicate the poverty."
The 57-year-old's first task will be heal deep political and regional divisions.
Last year, rival sections of the security forces fought in the streets as a breakdown in law and order quickly led to gang warfare, looting and arson that killed at least 37 people. Tens of thousands remain in makeshift shelters, too afraid to return home.
"If Ramos-Horta wins it will not be a victory over Lu-Olo but a victory for East Timorese democracy and values," said Maria Fernandes, a 46-year-old school teacher. "I hope Horta will be able to embrace all Timorese."
Guterres, a former guerrilla fighter, has pledged to accept the results, which do not bode well for the chances of Fretilin in more important parliamentary polls next month that will determine the country's prime minister.
"This is a devastating blow to Fretilin," said Mark Aarons, an author who has written about East Timor since the 1970s. "You would think now that the party will have to accept the people's judgment."
Ramos-Horta's political ally, outgoing president Xanana Gusmao, is planning to run for prime minister in a bid to sideline the left-wing Fretilin party, which many blame for last year's violence and general mismanagement of the country.
Despite sizable offshore oil and gas deposits, nearly half of East Timor's work force is unemployed, about 60 percent of children under 5 are malnourished, and tens of thousands of people displaced last year remain in tent camps.
Wednesday's poll followed a first round of voting last month that failed to produce an outright winner among eight candidates.