Defending champion Mandy Minella beat Naomi Gibbs in straights sets on day one of the Bol Open.
Minella won the inaugural tournament on the clay in Croatia last year and is through to round two 12 months on after ousting Gibbs 6-4 6-2.
The 31-year-old from Luxembourg was beaten by Kirsten Flipkens in the first round of the French Open last week, but the second seed responded with a routine success over the American.
She will now face qualifier Chuang Chia-jung, who defeated Tamara Zidansek 6-4 6-4 on Tuesday. Kateryna Bondarenko, another player beaten in the opening round at Roland Garros, saw off Viktoriya Tomova.
Olga Saez Larra, Alison Van Uytvanck, Olga Govortsova, Lina Gjorcheska and Beatriz Haddad Maia also made it into round two along with Alexandra Cadantu and Tereza Mrdeza.