Ecuador's presidential election looked headed to a runoff as partial results showed leftist candidate Lenin Moreno fell short of the lead needed to win outright in Sunday's first-round vote.

With 51.8 percent of the ballots counted, Moreno had 38.26 percent of the vote with 29.86 percent for his conservative rival Guillermo Lasso, said the president of the National Electoral Council, Juan Pablo Pozo.