Mr Correa said Ecuadoreans had made history with the poll
Ecuador's President Rafael Correa is on course for outright victory with more than two-thirds of the votes counted after Sunday's presidential election.
He has won more than 50% of the vote so far and has a big lead over his closest rival, ex-President Lucio Gutierrez.
"We've made history," said Mr Correa, who called the election under a new constitution designed to reform Ecuador's political institutions.
His opponents have accused him of using strong-arm tactics to retain power.
"We've made history in a nation that between 1996 and 2006 never saw a democratic government complete its term," said Mr Correa, who had been widely expected to win the vote.
With 70% of ballots counted, Mr Correa has 51.7%, Mr Gutierrez 27.8% and banana mogul Alvaro Noboa 11.6%, the National Electoral Council said on its website.
Mr Gutierrez said he would wait until the official results were released before accepting Mr Correa's victory.
Mr Correa's expected win means there will be no second round run-off vote in Ecuador for the first time in 30 years.
In addition to selecting the president, voters elected members of the National Assembly and regional and municipal offices.
Mr Correa first came to office in January 2007.
Since then, he has won a following through massively increasing social spending and talking tough to the foreign investors and multinationals many Ecuadoreans feel are exploiting their country.
Ecuador's new constitution gives prison inmates the vote
But these policies were formed as commodity prices hit record highs.
If the price of oil, Ecuador's main export, remains low, Mr Correa will have much less money to spend on social programmes.
The country's economy is also very reliant on the remittances sent home by the hundreds of thousands of Ecuadoreans living in Spain and the United States.
Foreign investors have also been put off by recent moves not to pay some of the country's debt, and by doubts about whether Ecuador will stop using the US dollar as its national currency.
Analysts say Mr Correa could fall quickly from grace if he is forced to tighten the purse strings after the election.
His opponents also accuse him of riding roughshod over the country's democratic institutions by backing the adoption of a new constitution in a popular vote last September.
Among other things, the constitution increased state controls on private industry and land and allowed Mr Correa to run for re-election.
It also gave 16-year-olds, prison inmates, police and soldiers the vote.