Louise Shanahan won the 800m at the World Indoor Tour Silver Level meeting in Belgrade on Monday night.
The Tokyo 2020 Olympian finished first in a time of 2:04.68, ahead of Jerneja Smonkar of Slovenia and the Netherlands' Suzanne Voorrips.
The Leevale AC athlete, who won 800m gold at the Irish Life Health National Senior Indoor Championships in February, was among four Irish athletes in action at the event on Monday.
Darragh McElhinney was third in the men's 1500m, setting a new national U23 record with a time of 3:39.63.
Olympians Cillin Greene and Christopher O'Donnell, who represented Ireland in the mixed 4x400 relay in Tokyo last summer and reached the final with a national record, were fourth and fifth respectively in their men's 400m heat.
The World Indoor Championships will also take place in Belgrade on 18-20 March.