The official Sunday results indicated that Luisa Gonzalez, the leading figure among the Leftists, appeared poised to compete against an unexpected contender – the young son of one of Ecuador's wealthiest individuals – in an upcoming run-off election scheduled for October.

With 80 percent of the votes tallied, Gonzalez, a lawyer with close ties to the polarizing former socialist president Rafael Correa, held the lead with 33 percent of the vote.

President of the National Electoral Council Diana Atamaint said results revealed no decisive winners after both candidates fell below the minimum vote count to score an outright win.

"We are heading to a second round election on October 15," she said in a briefing.

Daniel Noboa, 35, came in second place unexpectedly, garnering 24 percent of votes after the assassination of Fernando Villavicencio, a popular socialist candidate, a few days ahead of the elections.

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"We are celebrating because we are making history, even though so many of us have been ignored, today we begin moving toward a different history," Gonzalez told journalists and supporters at an event in southern Quito.

"The Ecuadorean people have won," Noboa, the son of a well-known businessman in the banana trade and former five-time presidential candidate Alvaro Noboa, told journalists in Guayaquil.

"The youth candidate, of the people who are seeking hope, who want to change Ecuador, has triumphed."

The South American country witnessed in recent years a rise in violence and the influence of competing drug cartels - which engage in local wars over territory and export disputes.

Six Columbian suspects linked to the drug scene were charged with Villavicencio's killing and are being held in custody. Another suspect died from wounds sustained in a shootout with the police.

Pedro Briones, a member of the Citizen Revolution Party and one of its leaders in the province of Esmeraldas on the border with Colombia, was also killed by unknown gunmen days before the elections.

Some experts considered that this stems from the bounce-back to neoliberal politics after former president Rafael Correa left office.

Gonzalez announced that former leader Correa will become a close aide in case she gets elected.

An anti-corruption probe led by Villavicencio sentenced Correa, who fled to Belgium and has been living there for six years in exile, to eight years in prison.

Construye Movement, the political party affiliated with the late Villavicencio, chose journalist Christian Zurita as his replacement for the elections. Zurita, also a close friend of the assassinated politician, came in third place with 16 percent of votes.

Read more: Correa's party rejects new Construye party candidate: Ecuador