(CNN) -- Victor Yushchenko, the politician brought to power in Ukraine's Orange Revolution five years ago, is struggling to hold onto the presidency as voters go the polls Sunday -- and the man accused of stealing the election in 2004 is a strong contender to win it legitimately this year.
That's Victor Yanukovich, a politician with strong links to Russia, swept aside by the Orange Revolution. With his party now leading opinion polls, analysts say he may be poised to take political revenge.
For five years, Ukraine's embattled President Yushchenko, his face still scarred by a mysterious poisoning, has struggled at the helm of this divided nation.
Yushchenko is now campaigning for a second term. But blamed for Ukraine's faltering economy, his ratings are in single digits -- and his rivals are vying to take over.
The number-one threat will come from Yulia Tymoshenko, his one-time Orange Revolution ally, he says, implicitly accusing her of planning to orchestrate "mass failures of vote counting and falsification."
Tymoshenko is Ukraine's populist prime minister who stood alongside Yushchenko during the pro-Western uprising that swept both to power in 2004.
Political infighting saw their alliance break down, and now she's campaigning for the top job, vowing to lead Ukraine into the European Union and NATO. But President Yushchenko isn't her main rival.
Tymoshenko urged Ukrainians not to "come to the elections with their eyes closed and bring the pure, powerful oligarchy, ready to own the country, back to power again."
There are a number of other candidates in the field as well, though analysts say none is likely to emerge with the simple majority needed to avoid a second round of voting. In fact, a date for that run-off has already been set for February 7 -- when Ukraine will finally choose a new leader and its future path.
CNN's Michael Sefanov in Moscow, Russia, contributed to this report.