The candidates in Peru's presidential run-off election are locked in a tight count after voting Sunday.
Liberal economist Pedro Pablo Kuczynski was ahead on 50.6 per cent with right-wing populist Keiko Fujimori on 49.4 per cent after 36 per cent of the votes had been counted, according to official results.
In the first round of voting in April, Fujimori, leader of the rightist Popular Force Party and the daughter of the country's imprisoned former president, won 40 per cent of votes to Kuczynski's 21 per cent.
But Kuczynski has rallied support from former rivals concerned about how Fujimori might continue the divisive legacy of her father, Alberto Fujimori.
The elder Fujimori ruled Peru with an iron fist from 1990-2000. He was convicted on human rights and corruption charges and is serving 25 years in prison. Supporters credit him with cracking down on the Maoist rebel group Shining Path and reforming the country's economy.
Kuczynski, 77, leads the liberal Peruvians for Change party.
Supporters laud his long experience in government as an economy and energy minister and cabinet chief, but he faces criticism for his advanced age and work as a lobbyist and investment banker in the United States.
About 23 million Peruvians are eligible to vote, 900,000 from outside the country. Peruvians between 18 and 70 are required by law to vote, and the last election saw an 82 per cent participation rate.
The winner is expected to take office July 28.