Kellie Harrington and Michaela Walsh both boxed their way through to the last 32 of the AIBA Strandja Multi-Nations Championships in Bulgaria.
World champion Harrington recorded a unanimous 5:0 victory over Polish fighter Aneta Rygielska to progress in the 60kg division, while 2018 European bronze medallist Walsh went through on a split decision, beating Wildad Bertal from Mauritius 4:1 in her 57kg bout.
Walsh will return to the ring on Tuesday as she looks to book her place in the quarter-finals of the tournament, while Harrington has a rest day ahead of her last-16 encounter on Wednesday.
However, two of the Irish nine-strong contingent bowed out at the first time of asking as Kiril Afanasev was beaten by Turkey's Mujahit Ilyas 4:1 on a split decision in the 91kg contest.
And 63kg hopeful George Bates was also eliminated, going out on a unanimous 5:0 decision to Aadkhuja Muydunkujaev from Ukraine.
In total, four Irish boxers will fight in Tuesday's action as Niamh Earley faces France fighter Wassila Likhardiri in the 51kg division, Aofie O'Rourke goes in the 75kg categoty against Bulgaria's Dobromiro Georgieve, while Emmet Brennan takes on Stephan Hrekul from Ukraine at 81kg.
Olympian Brendan Irvine must wait until Thursday to open his campaign in the 52kg quarter-finals as he faces Bashkim Bejoku from Kosovo, while 91kg prospect Gytis Lisinskas fights India's Singh Manjeet on Wednesday.