Leftist former Prime Minister Milos Zeman and conservative current Foreign Minister Karel Schwarzenberg will face each other in the runoff to become president of the Czech Republic.
Results from the first round vote on January 11-12 showed Zeman in first with 24.2 percent, followed by Schwarzenberg with 23.4 percent.
The result is considered somewhat of a surprise, as preelection opinion polls had not suggested the 75-year-old Schwarzenberg would poll so high.
Zeman, 68, was prime minister from 1998 to 2002.
The runoff will be held on January 25-26.
The vote to choose a replacement for outgoing President Vaclav Klaus marks the first time Czech voters are selecting a president in a direct popular vote.
Klaus is stepping down after serving the maximum two five-year terms in the mainly ceremonial presidential post.
Based on reporting by AP, Reuters, and dpa