But amid grave public disillusionment over five years of botched reform and political stalemate, Yushchenko appears set to drop out of the election race in the first round.
Hours before voting stopped, Al Jazeera's Neave Barker, reporting from Kiev, said voters had low faith in the fairness of the election.
"A recent poll suggested that only five per cent of the population believe this election will be free and fair and I don't think the front runners have done much to inspire confidence over the last week of campaigning.
"The two leaders, Yanukovich and prime minister Tymoshenko, have accused each other of planning to rig the election.
"But that said, the same poll indicated that the voter turnout could be as high as 75 per cent. While people may be disillusioned with the political elite, they're certainly not apathetic."
After a campaign that saw the main protagonists trade insults, all the main candidates spent the final hours of campaigning with appearances on Ukrainian political talk shows.
Yanukovich also held a glitzy rally in central Kiev attended by top Ukrainian pop stars.
Tymoshenko, her voice hoarse from weeks of campaigning, issued a stern warning against the perils of voting for Yanukovich, saying the country risked becoming "internationally isolated, ruled by oligarch clans and criminals".
Yanukovich replied: "What have the Orange leaders promised and not done over the last five years? They deceived the people."