Viktor Yushchenko, the politically bruised, outgoing Ukrainian president, cast his ballot Sunday without backing either of his two rivals for the post.
"The Ukrainians will be ashamed of their choice, but this is democracy," Yushchenko told reporters after voting. "Ukraine must learn to run fair, legal elections. The top priority today is to show the Ukrainians that we can hand over power in a democratic way."
He voted at Kiev Polling Station No. 1 with his wife. Earlier reports had said he was planning to vote against both candidates, and he refused to throw his support behind either of the front-runners.
Yushchenko fell out of the race in the first round of voting, winning just 5.45 percent to take a distant fifth place.
Viktor Yanukovych, who topped the first poll, lost his initial bid for the presidency five years ago in the Orange Revolution, led by Yushchenko and their now-mutual rival, Prime Minister Yulia Tymoshenko.
Yanukovych initially won the 2004 election, but the Supreme Court threw out the results after mass protests over falsifications. Yushchenko, a former Central Bank chief and prime minister, went on to win the rerun election and became president in January 2005, promising to rally Ukrainians to join the European Union.
His popularity dropped dramatically, however, after he failed to deliver on promises and infighting led to political deadlock.
Both Tymoshenko and Yanukovych have been accused by each other's supporters of planning to commit election fraud, although analysts say mass demonstrations are unlikely to be repeated.