Kellie Harrington was an easy winner on her return to the ring after the Olympics, outclassing Sweden's Agnes Alexiusson in the 73rd International Strandja tournament in Sofia.
Harrington won every round according to four of the five judges, 30-27, with the Estonian official giving Alexiuusson one round.
It was a routine fight for Harrington who will now move on to the next stage of the lightweight competition.
Harrington is one of six Irish fighters in action today.
Roscommon middleweight Aoife O'Rourke also won her bout, defeating Greece's Vasiliki Stravridou.
The remaining four Irish fighters struggled, none coming through their bouts.
Kelyn Cassidy was beaten on a 4-1 split decision by Nikita Nystedt of Finland.
The other three Irish fighters were all defeated via unanimous decision, Christina Desmond defeated by Russia's Galina Golovchenko, Adam Hession losing out to Uzbekistan's Abdulmalik Khalokov, while JP Hale fell short against another Russian, Artur Subkhankulov.