KIEV, Ukraine -- Volodymyr Zelenskiy, a comedian with no political experience who plays the country’s president on a TV show, has won Ukraine’s presidential election in a landslide, according to a national exit poll. The poll showed Zelenskiy receiving 73% of the vote, sweeping away Ukraine’s incumbent president, Petro Poroshenko, who conceded defeat.

At a campaign party in a bar in Kiev, packed with hundreds of journalists, Zelenskiy declared victory. As the exit poll’s results were announced, confetti was shot into the air and Zelenskiy thanked his campaign volunteers, saying they had “protected Ukraine.” Poroshenko announced he was conceding shortly afterwards.

The result places a 41-year-old political novice at the head of Ukraine, one of the poorest countries in Europe, which exists on a fault-line in the stand-off between the West and Russia. Ukraine is still locked in a war with Russia that has killed 13,000 people since 2014.

Speaking to journalists and a handful of supporters in the bar, Zelenskiy hailed his win as a symbol of political change for other countries in the region.

"I’m not yet officially the president, but as a citizen of Ukraine, I can say to all countries in the post-Soviet Union look at us. Anything is possible!"

Zelenskiy’s victory comes amid deep dissatisfaction among Ukrainians with their political establishment, and weariness with the war. He ran promising to fight corruption and upend the political elite, which is viewed as corrupt and indifferent to the concerns of ordinary Ukrainians.

At polling stations on Sunday, few voters expressed great affection for Zelenskiy, saying instead they supported him as an agent of change.

“I am for a new face,” said Tatiana Zakharenko, 50, an economist voting in central Kiev. “We need a change.”

Zelenskiy’s win had seemed likely since the first round of voting three weeks ago, when he beat a field of 40 other candidates, winning almost double the number of votes that Poroshenko received. The landslide on Sunday was a resounding rejection of the incumbent president, a 53-year-old billionaire confectionary tycoon who came to power on the back of mass protests in 2014 that toppled Ukraine’s then-Russian-backed president, Viktor Yanukovych. Poroshenko had campaigned as a wartime leader, promoting himself as a defender of Ukrainian identity against Russia, and warning that Zelenskiy’s experience would mean a victory for Russian president Vladimir Putin.

Poroshenko, though, has been unable to overcome widespread perceptions that he has failed to tackle entrenched corruption and continued Ukraine’s tradition of using power to enrich allies.

In his concession speech Poroshenko said he would remain in politics, “because our team must protect the achievements that we have made in extremely difficult conditions.”

He added that his supporters must prevent what he called the “Kremlin’s plans” to form a group loyal to it in Ukraine’s parliamentary elections in the fall.

Those voting for Zelenskiy said that their disappointment with Poroshenko was such that they were ready to take a risk.

“Poroshenko has taken the most important thing from the people. He has taken hope from the people,” Ruslan Kotsaba, a journalist who was charged with treason for criticizing the military draft ordered by Poroshenko. “At least with Zelenskiy it’s at least some kind of hope.”

Some said given the corrupt state of Ukraine’s politics, Zelenskiy’s lack of experience was actually a plus. “On the one hand, it’s not the best president for me, but at least he has no experience in corruption or all the things that our politicians have,” said Anna Dysheleva, a marketing executive, after voting with her young son.

Few know what that change will mean in practice. Besides promising to root out corrupt officials and find an end to the war, Zelenskiy has campaigned on almost no detailed policies. He has also has avoided the media, refusing interviews. The last interview he gave was to a journalist who won a ping pong competition on the night of his victory in the first round of voting. On Sunday, the same competition was running at the victory party.

Instead, Zelenskiy largely campaigned as a version of his on-screen persona, and held stand-up comedy shows instead of political rallies. In his show, “Servant of the People,” he plays a schoolteacher who is catapulted into the presidency when his rant against corruption goes viral. Once president, he eschews the traditional perks of his office and battles oligarchs who normally direct politics in Ukraine.

In reality though Zelenskiy comes to power with a relationship to one of Ukraine’s most controversial oligarchs, Ihor Kolomoisky. Many of those who voted for Zelenskiy expressed reservations about his ties to Kolomoisky, whose television channel, 1+1, airs his show, and who has supported his campaign.

Kolomoisky has been in effective exile, spending time in Israel since Ukrainian authorities nationalized his bank, Privat Bank, accusing him and associates of stealing billions of dollars from its account-holders.

This report was featured in the Monday, April 22, 2019, episode of ABC News' daily news podcast, "Start Here."

Many now fear that Kolomoisky will follow Zelenskiy into power. A Kiev court this week ruled the nationalization of Privat Bank was unlawful, further fueling worries among Zelenskiy’s critics.

Many who voted for him though said that in Ukraine, any candidate will have some kind of oligarch backing. “I think we can live with it,” said Evgeny Kozhevnikov, a 34-year-old engineer.

Zelenskiy himself has repeatedly said he will be his own man, promising to jail anyone found to have broken the law. He has succeeded in winning over many of the country’s activists and liberal reformers, who played important roles in the 2014 revolution and its aftermath, and who feel that its promise remains unfinished. A number of them, including former ministers have been seeking to advise Zelenskiy on his filling out his team.

Serhi Leshchenko, a prominent liberal journalist and member of parliament said he believed Zelenskiy’s huge result would help bolster his independence. At Zelenskiy's victory party, Leshchenko said that 75% or the vote was "more than enough to be independent." Leshchenko also he believed there was a strong chance for reformers to join Zelenskiy’s government now.

"There is huge room for people to join his team with reform-minded orientation," said Leshchenko. "I believe that he is a responsible, reliable person."

The challenges he faces as a political newcomer, though, are daunting. Those who voted against Zelenskiy worry what his election will mean for Ukraine’s relationship with Russia. Poroshenko has asserted Zelenskiy’s inexperience and his more moderate stance towards Russia — where he is also popular as a comedian -- will mean Ukraine under him could slide back into Moscow's orbit, a fear many voting for Poroshenko expressed Sunday.

Speaking before he voted on Sunday, Poroshenko said the possibility of Zelenskiy’s election was “not funny”, adding that it could lead to Ukraine’s return “to the Russian Empire.”

Many voters in Ukraine, though, say they are ready to see an attempt to resolve the violent impasse in the east, where shelling continues daily and there are casualties every month.

It remains unclear, however, how Zelenskiy would try to do that. He has previously said he would seek direct negotiations with the separatist forces that Moscow backs. But speaking after his victory, he told reporters only that he would continue to pursue talks through the so-called Normandy Format, with France and Germany, and continue with the Minsk Agreements, a peace plan that was implemented in February 2015 but which has long-since stalled.

Despite ambivalence about their options, many in Ukraine have expressed satisfaction that the election, however often chaotic, was truly competitive. Millions watched a stadium debate between the candidates his week that was more like the opening of a boxing match than a traditional political staple.

Diana Gabovich, a young woman voting in Kiev, was one of the few voters ABC News spoke to who expressed unalloyed support for Zelenskiy.

"The debate went well -- I laughed,” she said. "We’ll all be laughing, the whole country, in a couple of months.”