Slovakians began voting Saturday to choose a new president with the outcome determining whether the EU and NATO member shifts further towards Russia.
Ivan Korcok, a 60-year-old pro-Western ex foreign minister, and Peter Pellegrini, 48, a Ukraine-sceptic backed by the ruling populists, are vying to replace the outgoing liberal President Zuzana Caputova.
They are squaring off in a decisive second round as neither won the minimum 50 percent in last month's ballot.
Though the office is largely ceremonial, Slovakia's president ratifies international treaties, appoints top judges, is the commander-in-chief of the armed forces and can veto laws passed by parliament.
The final pre-election poll by the Focus agency put Korcok and parliament speaker Pellegrini neck-and-neck, with Pellegrini gaining 51 percent of the vote and Korcok 49 percent.
"This is the tightest ever presidential race," said Vaclav Hrich, managing director of the AKO polling agency.
Stefan Harabin, who placed third after criticising the European Union and hailing Russian President Vladimir Putin, did not formally back either candidate.
"It is an important 12 percent that Harabin got," political analyst Tomas Koziak told AFP, adding that "Korcok is unlikely to win those votes".
According to AKO, over two thirds of Harabin voters intend to support Pellegrini.
Yet Hrich said the election was "too close to call" and said turnout will be decisive.
"The more people vote, the more chances Peter Pellegrini will have as this would mean he had succeeded convincing Harabin's voters," he said.
Russia's invasion of Ukraine became a fixture of the electoral campaign in the country of 5.4 million after Prime Minister Robert Fico questioned the sovereignty of Ukraine and called for peace with Russia.
Pellegrini was a minister in Fico's previous governments and was head of government from 2018 to 2020 when his long-time ally was toppled.
"I am running for president to rescue the government of Robert Fico," Pellegrini said in a televised debate.
Korcok fired back: "You want to protect the government. I want to protect Slovakia."
Fico's government that took office in October includes his Smer party, Pellegrini's Hlas and the small far-right SNS, and has discontinued military aid to Ukraine.
"Korcok is a warmonger, who will support everything the West tells him without hesitation, including dragging Slovakia into the war," Fico said in a video.
He expressed support for Pellegrini, calling him "a moderate candidate who recognises the value of peace".
Pellegrini said "the Slovak political scene is divided between those who are in favour of the continuation of the war at all costs, and those who demand the start of peace negotiations".
"I belong to the latter," he told AFP.
Korcok, a vocal government critic backed by the opposition, is staunchly pro-Ukraine.
"The Russian Federation has trampled on international law. I do not think Ukraine should give up part of its territory to achieve peace," he told AFP.
Pavol Turanec, an electrical designer from Martin, northern Slovakia, hailed Korcok.
"Korcok is a real pro: pro-democratic, pro-Western, pro-European. His values do not change depending on polls," the 50-year-old told AFP.
"This criminal government is leading us to a pro-Russian autocracy, devastating the judiciary, and public finances. They really need a counterweight."
Jana Mozolova, a retired teacher from the eastern city of Kosice, said Pellegrini had her vote.
"He is the only candidate to ensure no Slovaks would have to fight in the war," the 66-year-old told AFP.
"He has been around for years and never let anyone down."
Polling stations opened on Saturday at 7:00 am (0500 GMT) and will close at 10:00 pm.
Provisional results are expected around midnight.