- According to the first exit poll released on Sunday evening, Comedian Volodymyr Zelensky won the first round of the Ukraine presidential election with 30.4% of the vote.
- President Petro Poroshenko came second with 17.8% of the vote, according to the same exit polls.
- Announcing the first poll, the Central Election Commission said it was based on voting up to 18:00 (15:00 GMT).
- If no candidate receives more than half the votes, the election goes to a run-off on April 21.
Ukrainians cast their votes on Sunday in a presidential election that could shape the country's future for decades to come, with a comedian who has no political experience the favourite to take the helm of a country ravaged by military conflict and an ailing economy.
With a long list of 39 names on the ballot, the nation is choosing a leader to steer Ukraine's economic growth, end an ongoing conflict with Russia-backed separatists in the east and fight rampant corruption.
Comedian Volodymyr Zelensky has been consistently leading opinion polls for months ahead of the election, with President Petro Poroshenko and former Prime Minister Yulia Tymoshenko trailing far behind.
Polls closed at 8 p.m. local time (1 p.m. ET) and preliminary results could be in as soon as Monday morning.
Should none of the candidates get more than 50 per cent of the vote, a runoff election between the top two will be held on April 21.
Whoever ultimately takes power will have to grapple with neighbouring Russia — which backed separatists in Ukraine's east and annexed Crimea in 2014.
None of the three top candidates has positioned themselves as friendly to the Kremlin, an unwelcome association in the country's current political climate.
Poroshenko swept to power in May 2014, months after mass protests forced the ouster of Putin-backed Viktor Yanukovych.
Former Prime Minister Yulia Tymoshenko ran against Poroshenko and finished a distant second.
This time around Tymoshenko, 58, has played heavily to the economic distress of millions of Ukrainians, promising to enact legislation that will reduce prices of household gas by 50 percent immediately after taking office. She is also keen to keep the country on the pro-European path it embarked on after the 2014 revolution.
Poroshenko, a 53-year-old confectionery tycoon whose popularity has sunk amid Ukraine's economic woes and a sharp plunge in living standards, has been accused of turning a blind eye to corruption.
His time in office has also been marred by a defence spending scandal that broke out in the middle of the campaign in February.
Poroshenko has focused his election platform on support for the army and Ukrainian language.
In a move that prompted international criticism, Poroshenko has also banned Russian citizens from becoming election observers and said no election ballots will be allowed to be cast by Ukrainians living in Russia.
Zelensky, a successful actor and producer, has led an unconventional campaign aimed at engaging voters on social media.
In a case of art potentially imitating life, he played the Ukrainian president in a popular TV show.
Zelensky, 41, didn't hold rallies, instead traveling around the country selling tickets to gigs at which he parodied many of the politicians he is running against.
He has pledged to tackle corruption, stop a brain drain out of the country and make Ukraine "prosperous" again. He has also previously said that if elected he will only serve for one term.
Voters in the historically Russian-speaking southeastern regions of Ukraine could be crucial for Zelensky, who is a native Russian speaker.
Zelensky has also managed to engage a younger section of the electorate, but whether they actually buck historical trends and turn out to vote remains an open question.
Concern about the election's fairness spiked this week after the interior minister said his department was "slammed" by numerous claims that campaigners for Poroshenko and Tymoshenko were trying to bribe voters.
Many political observers have described the election as a battle between Ihor Kolomoyskyi — the self-exiled billionaire businessman alleged to be backing the comedian front-runner — and Poroshenko, who was himself on Forbes Magazine's list of billionaires in 2014.
Both the president and Kolomoyskyi have relied on an arsenal of media outlets under their control to exchange blows.
Just days before the vote, Kolomoyskyi's TV channel aired a new season of the "Servant of the People" series starring Zelensky.
The comedian may soon be playing the president for real.