Mr. Gutiérrez, 45, had 54 percent of the vote to 46 percent for his adversary, Álvaro Noboa, 52, a banana tycoon who spent handsomely to try to cast himself as a populist.

The victory for Mr. Gutiérrez, a career military man with no other experience in public office, was seen as a reflection of widespread discontent with traditional politicians, who are viewed by many as corrupt purveyors of a status quo that favors special interests at the expense of most Ecuadoreans.

"Ecuador can begin to convert itself into a more just country, a more honest country, a country with a better living standard and a country that is authentically democratic," Mr. Gutiérrez told a television interviewer this evening.

Mr. Gutiérrez is the latest politician to benefit from the disenchantment many Latin Americans have with traditional political parties that followed free-market prescriptions pushed by the United States and multinational lending agencies. Most countries in Latin America have seen little tangible benefit from these steps, with poverty rising and living standards falling.

In Brazil, a former labor leader, Luiz Inácio Lula da Silva, won election last month, and in Bolivia and Peru populist, left-leaning movements surged in recent elections.

"He and other leftist candidates in Latin America see the leftist populist position as the place to be," said Larry Birns, director of the Council on Hemispheric Affairs, a Washington-based policy analysis group. "That orientation is no longer exotic. It has become mainstream for Latin America."

Mr. Gutiérrez survived a late surge by Mr. Noboa, who saturated the airwaves with commercials that depicted his opponent as a dangerous radical. In all, Mr. Noboa spent more than $1 million on media advertisements, $800,000 more than permitted. Mr. Gutiérrez also overspent, but by $56,000.

Mr. Noboa, who inherited one of Latin America's great fortunes and is considered the richest man in Ecuador, portrayed himself as a populist friend of the underclass. But he has been accused of employing children and mistreating workers on his banana farms, and analysts said his plans for governing had remained unclear.

"Noboa left more doubts than Gutiérrez," said Simón Pachano, a political analyst at the Latin American Faculty on Social Sciences in Quito. "There was a lack of confidence with Noboa."

With his dark skin and features indicating some Indian heritage, Mr. Gutiérrez struck a chord in a country where a small minority of white businessmen and politicians have always ruled.

"He will help the poor," said Marco Binicio, 30, a graphic designer, who voted today in the city center. "He says why give more to those who already have?"

Mr. Gutiérrez began an aggressive campaign two years ago to reach out to Ecuador's Indians, its trade unions and left-wing parties. His strategy was to cast himself as a patriot and corruption fighter speaking out for the 60 percent of Ecuadoreans who live in poverty.

"We started in my old car, three or four people, running around Ecuador, eating in the car, sleeping in the car," he said today. "Little by little, we began to reach people."

Mr. Guttiérez, a former pentathlete who entered the military academy at 15, started down the path of the classic Latin American strongman. Leading a group of military officers who joined an Indian uprising in 2000, Mr. Gutiérrez became the most visible leader in the coup that toppled President Jamil Mahuad, whose administration was reviled as indecisive, inefficient and corrupt. Mr. Mahuad's democratically elected predecessor was removed from office.

Mr. Gutiérrez was part of a three-man junta that lasted only a few hours before being dissolved and the vice president, Gustavo Naboa, took over, many here believe under pressure from the United States. Mr. Gutiérrez was promptly jailed, but on his release a few months later formed a political party, the Jan. 21 Patriotic Society, named after the date of Mr. Mahuad's overthrow.

In its manifesto, the party promises "war to the death" on corruption, to look for an alternative to the dollar, which became the official currency in 2000, and to reconsider ways to pay the foreign debt without affecting social programs.

Yet Mr. Gutiérrez's statements, particularly since finishing first among 11 candidates in the first round of voting on Oct. 20, has shifted to the political center. With investors jittery about his first-round victory, he traveled to the United States last month to meet with economists and officials of multinational lending agencies.

"The next government will not be an Indian government or a government of the left," said Mr. Pachano, the political analyst.

"The challenge is to make a government that can govern and have accords with the Congress. Without those deals with Congress, he is not going anywhere."