Tobacco tycoon Horacio Cartes was elected as the new leader of Paraguay on Sunday after securing almost half of the votes.
It returns the conservative Colorado Party to the presidency that it held for 61 years before former Roman Catholic bishop Fernando Lugo won the office in 2008.
Mr Cartes won a five-year term with 46% of the vote over 37% for Efrain Alegre of the Radical Liberal party, the Electoral Court announced after most votes were counted. Five other candidates trailed far behind.
Turnout was more than 68% among the estimated 3.5 million of Paraguay's 6.2 million citizens who are registered to vote.
The president-elect said: "I'll need help from all the Paraguayans to govern in the next five years. Poverty, the lack of jobs for young people and international issues await us."
The UN estimates that more than half of Paraguayans live in poverty.
Mr Alegre accepted his defeat despite saying earlier that he might challenge the outcome. "The Paraguayan people have spoken. There's nothing more to say," he said in a brief concession speech.
Mr Cartes, 58, is part of the tiny elite that controls almost everything in Paraguay. His father represented the Cessna aeroplane company in Paraguay, which enabled Mr Cartes to be educated in the US.
The president-elect owns controlling shares in banks, investment funds, agricultural estates and tobacco plantations. Most opinion polls predicted his victory, despite this being his first run for public office.
Mr Cartes is well-known in Paraguay as president of Libertad, the club that won last year's national football championship. Many Paraguayans hope the election will encourage other countries to restore full relations that were suspended after last year's impeachment of Mr Lugo, which neighbouring nations saw as a threat to democracy in the region.