Russia-friendly candidate Viktor Yanukovych held a narrow lead Monday in a presidential election that seemed likely to spawn a court challenge from his opponent.
There was no sign, however, that Prime Minister Yulia Tymoshenko was following up on her vow to bring protesters onto the streets in the event of defeat.
A Yanukovych victory could restore much of Moscow's influence in a country that has labored to build bridges to the West. It would close a chapter in the country's political history that was been defined by the 2004 pro-democracy Orange protests.
Some Ukrainians fear he could bring a retreat from Western democratic reforms and the muzzling of media and opposition parties.
Central Election Commission data showed Yanukovych garnering 48.23 percent to Tymoshenko's 46.14 percent, with about 5 percent of ballots remaining to be counted.
Yanukovych has claimed victory and his team kicked off festivities by calling on the prime minister to stay true to her claim of being a democrat and admit defeat. Around 5,000 of his supporters assembled Monday morning near a stage in Kiev adorned with the slogan "Ukrainians for a Fair Election," claiming to defend the results of the election.
Supporters danced in the street as a series of daylong concerts got under way despite frigid temperatures and flurries of snow. Hundreds waved Yanukovych's signature blue campaign pennants and some draped flags over their shoulders, readily admitting they were there to forestall attempts by the Tymoshenko camp to organize large-scale protests.
There was no word from Tymoshenko's camp by early Monday.
Tymoshenko, who became an international figure during the Orange Revolution, wants Ukraine to integrate more closely with the European Union and form an identity independent of Russia.
She has vowed to challenge a vote she claims was rigged in Yanukovych's favor, as it was in the 2004 election that set off the Orange Revolution. After weeks of demonstrations, a court threw out the results of that vote and Yanukovych lost a court-ordered revote to outgoing President Viktor Yushchenko, then a Tymoshenko ally.
Sunday's race narrowed sharply from the first-round vote on Jan. 17, when Yanukovych held a 10 percentage point lead.
The election commission projected the turnout among Ukraine's 37 million voters at just under 70 percent, 3.2 percentage points higher than the first-round vote, in which 18 candidates competed.
Many election observers have already hailed the transparency of the voting process.
Ukraine's Central Election Commission said late Sunday there was no evidence of large-scale fraud, but it expects that the loser will challenge the results in court.