Opposition leader Viktor Yanukovich has a lead of more than 10 percentage points over Prime Minister Yulia Tymoshenko in the first round of Ukraine's presidential election with 99.31 percent of the ballots counted, preliminary official results showed on Monday.

Supporters of Opposition leader Viktor Yanukovich celebrate Yanukovich's leading in the Ukrainian presidential election with 80.27 percent of all the ballots counted, in Kiev, capital of Ukraine, Jan. 18, 2010. Yanukovich gained 35.76 percent of the ballots counted, while his main challenger, incumbent Prime Minister Yulia Tymoshenko, garnered 24.72 percent, according to the Central Election Commission. They are scheduled to compete in a run-off vote on Feb. 7. [Lu Jinbo/Xinhua]

Yanukovich gained 35.41 percent of the vote, while his main challenger Tymoshenko won 24.98 percent, according to the Central Election Commission. They are set to enter a run-off on Feb. 7.

The results also showed that 13.05 percent voted for Sergei Tigipko, a former economy minister. His supporters are now crucial in determining the results of the second round.

The country's incumbent President Viktor Yushchenko had a total defeat in the first round, scoring 5.46 percent of the vote.

Official results will be published on Jan. 27.

Sunday's vote was Ukraine's first presidential election since the 2004 Orange Revolution. Preliminary data showed that the turnout was 67 percent.

Over 3,000 international observers monitored the election. The mission of the Organization for Security and Cooperation in Europe (OSCE) described the poll as "quiet and well organized."

"The first round was held at a high level, demonstrated significant progress compared to the previous election campaigns, and complied with most standards of the OSCE and the Council of Europe," the mission said in a statement.

Yanukovich, leader of the Party of Regions, said Ukraine will be a reliable and predictable partner for other countries.

"As for our partners, our neighbors, they would certainly like to deal with a country and leaders who are reliable and predictable," he told a press conference.

Although international observers pointed to some flaws, the election was transparent and honest, he added.

Yanukovich, who draws the bulk of his support from the Russian- speaking areas of the industrial east and the south, has promised Ukrainians economic revival, new jobs, pay raises, judicial reforms and tax-free policies for small enterprises for five years.

Tymoshenko, an ally of Yushchenko in the Orange Revolution, gave priority to a fair society and government efficiency, and pledges an innovation-driven economic structure reform and improvement in people's welfare. Her powerbase is in the west of the country.

Both leading candidates have pledged to mend ties with neighboring energy supplier Russia.