Twenty candidates were in the running for Peru's presidency in the 9 April elections which became a three-way race with no candidate getting the 50% of the vote necessary to win outright.
After a protracted vote-count, the two candidates through to the run-off on 4 June are Ollanta Humala and Alan Garcia, who squeezed out Lourdes Flores.
OLLANTA HUMALA - UNION FOR PERU
Ollanta Humala, 42, a self-proclaimed nationalist and former army officer, is a political unknown.
He first came to public attention when he led a military rebellion against the government of Alberto Fujimori in 2000.
Although he describes himself as a "nationalist" and not a "leftist", during his campaign Mr Humala has been keen to associate himself with left-leaning leaders such as Brazil's Luiz Inacio Lula da Silva and Argentina's Nestor Kirchner.
However, his rhetoric places him closer to Venezuela's Hugo Chavez and Bolivia's Evo Morales, something that has unnerved US officials and foreign investors.
Mr Humala says he intends to rewrite the constitution in order to "stop the process of neo-colonialism in Peru" and is emphatically opposed to the signing of a free trade agreement with the United States.
He has threatened to review contracts signed with international companies and to impose a "windfall tax" on foreign mining firms.
Although Mr Humala has toned down his nationalist rhetoric during his campaign, his success in the polls has sent jitters through Peru's stock markets and many foreign firms have put investments on hold until the outcome of the elections is known.
Support for Mr Humala is concentrated among Peru's poor rural population, who believe he can offer an alternative to the corruption and sleaze of traditional politics.
However, his campaign has been overshadowed by allegations of human rights violations committed while he commanded a military battalion in the battle against Shining Path rebels in 1992.
His support has also been weakened by President Chavez's apparent endorsement of his candidacy and his perceived lack of a firm policy programme.
ALAN GARCIA - AMERICAN POPULAR REVOLUTIONARY ALLIANCE
Alan Garcia, 56, is a former president whose time in office left the country in financial chaos.
Despite a legacy of hyperinflation, rebel violence and alleged human rights violations, Mr Garcia remains popular among many Peruvians and his campaign has focused heavily on attracting the youth vote, many of whom have only vague memories of his time as president (1985-90).
He has also launched a bid to woo female voters away from Ms Flores, promising to appoint an equal number of women and men in his cabinet, and to achieve equal pay for both sexes.
Mr Garcia has promised to create thousands of jobs and to divert more of the country's mineral wealth to the poor by taxing mining firms' profits.
He has also said his government would focus on attracting foreign investment and promoting agriculture, warning that if Peru does not invest now, "it will become a colony of Chile".