The soaring popularity of Ukrainian comedian Volodymyr Zelensky, who led the first round of presidential polls, has intrigued Russians with many warming to his calls for dialogue with Moscow, and laughing along with his Russian-language humour.

The Kremlin has so far avoided voicing an opinion on the 41-year-old actor, who won 30 percent of the vote on Sunday after emerging as a surprise favourite in the race against political heavyweights.

President Vladimir Putin's spokesman Dmitry Peskov said only that Moscow does not want a "party of war" in power in Ukraine, seemingly referring to incumbent Petro Poroshenko, who came second in the first round on 16 percent and now faces a run-off, with nearly 90 percent of votes counted.

Some observers suggested the Russian leadership would like Zelensky to win because a political novice is likely to make blunders, propping up Moscow's narrative that Ukraine has descended into chaos after turning its back on neighbouring Russia.

Yet for some ordinary Russians, jaded by five years of political deadlock between Moscow and Kiev, Zelensky comes as a refreshing change.

"Finally a kind of breath of fresh air in Ukraine's morass," said Ruslan Shuyev, a 23-year-old IT specialist.

"He speaks Russian, he's funny and he's not corrupt... yet," said his companion, 21-year-old Irina.

For 38-year-old lawyer Maxim Vorobyov, Zelensky is "less anti-Russian, he's young and dynamic and at the end of the day he's not the worst of Ukraine's candidates."

While Zelensky plans to continue Kiev's pro-Western course, he backs talks with Moscow to end the conflict with Russian-backed separatists in eastern Ukraine.

Unlike his rival Poroshenko, Zelensky has not built his campaign around identity politics and thorny issues of language and religion.

He has promoted himself mostly through social media and with standup appearances at comedy gigs that are largely in Russian and riff on cultural references as familiar to Russians as Ukrainians.

- 'Incredible charisma' -

Through "a huge number of references to the Soviet past shared by Ukrainians and Russians, Zelensky is the candidate Russians find easiest to understand," said Russian political analyst Gleb Pavlovsky.

The political rift between the countries since the 2014 annexation of Crimea and the outbreak of the separatist conflict in eastern Ukraine that has killed some 13,000, has slashed through cultural ties as well.

But that does not erase the shared cultural heritage of Russians and Ukrainians: Russian literature, Soviet and post-Soviet films, songs and television shows, including the long-running series that gave Zelensky his break as a comedy performer.

Zelensky made his debut on KVN, a hugely popular comedy contest between teams of students that first aired in the Soviet era. In 1997, he was part of a winning team of students from his central Ukrainian home city of Kryvyi Rig. At the time the show was watched widely in Ukraine as well as in Russia.

For 10 years, his troupe toured regularly in Russia. He also appeared in a popular Russian-Ukrainian-produced comedy film called "Love in the Big City" that spawned two sequels.

"Zelensky is one of the five most popular comic actors in Russia now," the film's director Marius Weisberg said, adding that he's proud of "having discovered... this actor of incredible charisma."

- 'Imminent disaster' -
Zelensky's career in Russia halted abruptly after Moscow's annexation of Crimea and the following separatist conflict in the Donbass region of eastern Ukraine, his former Russian producer Sergei Livnev told AFP.

Yet Russians could still go online to watch his standup shows or his television show "Servant of the People" where he plays a teacher who is elected president of Ukraine.

Zelensky has said he is ready to negotiate with Putin face-to-face if the Kremlin strongman agrees to return Ukraine's territory.

"If I meet Putin, I'll say to him: 'So you've finally given us back our territory, how much more are you ready to give as compensation money for taking away our land and helping those who took part in the escalation in Crimea and Donbass?'," Zelensky said Sunday.

Many Russians are following Ukraine's election, with 79 percent telling VTsIOM state pollsters they had heard about it, even if 59 percent anticipated no change in relations between the two countries.

While Zelensky is appealing to some, other Russians are simply rubbing their hands at the havoc he could wreak as leader, said sociologist Olga Kryshtanovskaya.

"Some people in Russia are gloating... looking forward to disaster for our brother nation that is about to vote in a comedian as president," she said.