(CNN)His margin of victory is a fraction of a point but it's enough to give Pedro Pablo Kuczynski the presidency of Peru, with opponent Keiko Fujimori conceding defeat on Friday.
Kuczynski wins Peru presidential vote as Fujimori concedes
A final tally showed Kuczynski took 50.122% of the vote, while Fujimori, daughter of disgraced former President Alberto Fujimori, took 49.878%. Kuczynski cannot be named president-elect until the national electoral college makes the vote official.
Kuczynski, 77, claimed victory Thursday, saying on Twitter, "Thank you Peru, it is time to work together for the future of our new country."
A former World Bank executive and former prime minister of Peru who has also served as finance and energy ministers, Kuczynski ran for president the first time in 2011. He came in third in that race, behind Keiko Fujimori and current President Ollanta Humala. Kuczynski had refused to renounce his American nationality, which had become a campaign issue.
Known as PPK, he has since renounced his U.S. citizenship, although he is married to an American woman and his children live in the United States.
Kuczynski will take over Peru's government on July 28. Peru's constitution barred Humala from seeking a second term.
In her concession appearance at a news conference Friday, Fujimori stressed that her party will fill the role of opposition vigorously.
"We will be a responsible opposition that will think of the future of the country, having the compass to represent the feelings of those more than 8.5 million Peruvians who voted for (her campaign platform)."
"We democratically accept these (election) results," she said, adding, "We wish much luck to Pedro Pablo Kuczynski and his campaign allies."
Fujimori's father, Alberto, was president from 1990 to 2000. He is credited with restoring economic stability and with defeating the Maoist Shining Path guerrillas, who carried out terrorist attacks. But his authoritarian style led to accusations of human rights abuses and corruption.
In separate trials, Alberto Fujimori, the son of Japanese immigrants, was found guilty of authorizing illegal wiretaps and bribing lawmakers and journalists. He was also convicted of using public money to pay the country's spy chief and with burglarizing the spy's chief's house to steal incriminating videos.
In 2009, he was sentenced to 25 years in prison after being convicted of authorizing the operation of a death squad responsible for killing civilians. He remains in prison.