PRAGUE—Czechs voted in the first round of presidential elections Friday and Saturday and a world power was on the ballot: Russia.

President Miloš Zeman is seeking a second term and has cast himself as Vladimir Putin’s partner in Europe. Prague’s relationship with Moscow is “10 times” more important than with neighbors like France, he told the Russian president in November, chitchatting in Russian in front of journalists who he berated for their inability to speak the language.

The 73-year-old has also proposed a referendum asking Czechs if they want to leave the European Union and the North Atlantic Treaty Organization.

With ballots from almost all polling stations counted by the Czech Statistics Office on Saturday, Mr. Zeman had a big lead with 40% of the vote, according to the Associated Press. However, as he lacks a majority, Mr. Zeman and runner-up, Jiří Drahoš, will face a runoff election Jan. 26.

Mr. Drahoš, a 68-year-old former President of the Czech Academy of Sciences, is more western-oriented than Mr. Zeman. The latter’s praise for Mr. Putin—which extends to approval of his Crimea annexation and his airstrikes on Syrian cities—has bewildered many Czechs, but hasn't been an issue for his core voters.