The candidate of a united opposition front claims he has ousted the sitting president of the Maldives.
Ibrahim Mohamed Solih holds an unbeatable lead over Abdulla Yameen, with 437 of 472 ballot boxes counted, media in the Indian Ocean islands say.
But the national electoral commission has not yet announced any results.
Observers had believed the election was rigged in favour of Mr Yameen, who favours closer ties with China, while Mr Solih leans towards India.
President Yameen's government stands accused of crushing dissent.
Police raided opposition headquarters on the eve of the vote.
Mr Solih said his win was "a moment of happiness, a moment of hope" and urged a peaceful transition of power for the Indian Ocean archipelago.
He said he had won by a 16 per cent margin over Mr Yameen, with 92 per cent of votes counted.
The head of Mr Solih's Maldivian Democratic Party said the result would "bring the country back to the democratic path".
The European Union and US voiced concerns about the election, with both threatening to impose targeted sanctions if the democratic situation did not improve.
The Maldives is made up of 26 coral atolls and 1,192 islands, and tourism is a vital part of its economy. More than 0.4 million (400,000) people live there but its future hangs in the balance due to climate change.
Polls opened at 08:00 (03:00 GMT) on Sunday, and closed three hours later than expected, at 19:00, due to long queues.
