|Low-income voters were expected to hand a victory to Humala, who has talked about fair distribution of wealth [AFP]
Ollanta Humala, a left-wing nationalist, has won the first round of Peru's presidential election and looks set to face Keiko Fujimori, a rightist politician, in a June 5 run-off, three exit polls show.
Humala, 48 - who just missed out on the 2006 presidency - would win between 31.6 and 33.8 per cent of the vote, according to unofficial results broadcast as voting closed at 4pm local time on Sunday.
A Peru official said that 18.2 per cent of the votes had been counted in the official results as of 8pm local time.
In the run-up to Sunday's election, Humala had a lead over his three leading rivals, who are favoured by big business in one of the world's fastest-growing economies.
However, Fujimori's lead over the third-placed candidate, Pedro Pablo Kuczynski, was narrow, meaning Kuczynski could still have a chance of contesting the run-off, the polls showed.
"Ollanta Humala is a clear front-runner," Mariana Sanchez, Al Jazeera's correspondent, reported from Lima before the polls were announced on Sunday.
"But polls say that no candidate will be able to reach the 50 per cent plus one vote needed to win, so clearly there will be a run-off."
Despite a decade-long boom, a third of Peruvians live in poverty and low-income voters were expected to hand the victory to Humala.
Norma Correa, a social policy analyst at the Catholic University of Peru in Lima, told Al Jazeera that Humala's popularity was a reflection of a widespread desire for change, and for economic redistribution of the national wealth in particular.
However, given his lack of a decisive majority in the first round, Humala was unlikely to be able to govern alone, she said.
"He needs to establish alliances with other political forces."
A Datum exit poll gave Humala 33.8 per cent of the vote, followed by Fujimori with 21.3 per cent. Pedro Pablo, a former prime minister, Kuczynski had 19.5 per cent and Alejandro Toledo, a former president, 15.2 per cent.
The results were similar in an Ipsos exit poll that showed Humala with 31.6 per cent, Fujimori with 21.4 per cent, Kuczynski on 19.2 per cent and Toledo, 16.1 per cent. A CPI poll gave a similar reading.
Humala''s rivals have sought to hurt his chances by saying he would step up state control over the economy, rolling back reforms and jeopardising some $40bn of foreign investment lined up for the next decade in mining and energy exploration.
But Humala has surged in the race by shedding his hardline image and recasting himself as a soft-left leader in the vein of Luiz Inacio Lula da Silva, the former Brazilian president.
He has promised "gradual" change to ensure the country's decade-long boom reaches the one-third of Peruvians who have been left behind in poverty.
"Although there's an economic boom here, no candidate has made a clear plan about how they plan to tackle poverty," Al Jazeera's Sanchez said before the polls were announced.
"Ollanta Humala is really the favoured candidate because he's the only one who has talked about a fair distribution of wealth."