Team Ireland's Aoife O'Rourke and Michaela Walsh have both advanced to the last-eight of their respective weight classes at the 72nd Strandja Multi-Nations in Sofia, Bulgaria.
O'Rourke overcame home fighter Dobromiro Georgieve with a second round stoppage in their last-16 middleweight bout.
The Castlerea fighter will face the winner of the fight between Poland's Elzbieta Wojcik and Sennur Demir of Turkey in the quarter-finals on Thursday.
Walsh beat Yodgoroy Miraeva of Uzbekistan to progress to the quarter-finals in the featherweight ranks.
The Antrim native will face Poko Hlimi (Tunisia) or Karina Tazabekova (Russia) on Thursday.
But there were defeats for the two other members of the nine-strong Irish squad in action on Tuesday.
Niamh Earley lost to France's Wassila Likhardiri in their flyweight encounter, while Emmet Brennan was defeated by Stephan Hrekul of Ukraine in the men's light heavyweight class.