Karamarko has unofficially won 477 votes, Kujundzic 296, Jadranka Kosor 233, Darko Milinovic 55 and Domagoj Milosevic 34 votes.
Also unofficially, Drago Prgomet won the most votes for HDZ deputy president, followed by Ante Sanader and Andrej Plenkovic.
Kujundzic said he and Karamarko would compete in the runoff and that he expected to win.
"I will win in the runoff," he told Hina at the party's 15th general assembly.
The vote count is expected to end around 10 pm.