Opposition Social Democratic Party candidate Ivo Josipovic will face current Zagreb mayor Milan Bandic running as independent on January 10, the election commission said on its website, citing provisional results.
Based on over 98% of the ballots counted, Josipovic has won 32.44% of the vote, while Bandic has received 14.84% support.
Twelve candidates were competing in the first round to succeed President Stipe Mesic for the largely ceremonial post of Croatian head of state. A majority of more than 50% of the valid votes was needed for an outright win.
Eligible voters in Croatia are around 4.5 million.