The left-wing Correa danced, sang his party anthem and pumped fists with his close political advisers in his home city of Guayaquil on hearing the news.
'Revolution on the march'
"This revolution is on the march, and nobody and nothing can stop us," the 46-year old said.
"This is a war of information"
Lucio Gutierrez, candidate and former president
"We will never defraud the Ecuadorean people," he told cheering supporters.
"I think that's why we received such immense support. We've made history in a nation that between 1996 and 2006 never saw a democratic government complete its term."
Lucio Gutierrez, a former president, was in second place in the quick count, taking 30.5 per cent, and has not yet conceded defeat.
"The results announced aren't official, don't give up the vote count," said Gutierrez, who received between 24 and 31 per cent in exit polls.
"This is a war of information," he added, claiming "fraud" had been committed.
The country also held assembly and municipal elections, but with about 6,000 seats at stake, the results were not expected on Sunday.
International observers from the EU and the Organisation of American States reported no serious irregularities in voting.
Correa now has to deliver on promises of job and housing provision or face the scorn of Ecuadoreans, already suffering due to a weakening oil and banana-based economy.
Since winning the presidency in November 2006, Correa has won three national votes, including a referendum that ushered in Ecuador's 20th constitution since its founding in 1830.
He had about two years remaining on his current term, but the new constitution brought in last year allowed him to run for a fresh term.
Ecuador is into its third decade of democratic rule, after military rule ended in 1979.