Paddy Barnes, Tommy McCarthy, Jason Quigley and John Joe Nevin have booked places in the quarter-finals of the European Amateur Championships in Minsk.
Barnes, favourite going into this afternoon's bout, overcame Welshman John Williams courtesy of a unanimous points decision.
The light flyweight bout was scored 29-28, 30-27, 30-27 in favour of the Belfast boxer.
Barnes was joined in the quarter-final line-up soon after by heavyweight Tommy McCarthy.
McCarthy, also from Belfast, overcame Tomi Honka of Finland, also on an unanimous points decision, with all three judges scoring the fight 30-27.
Donegal boxer Jason Quigley advanced in the middleweight division, with a unanimous win 30-27, 29-28, 29-28 over Austrian Arbi Chakaev.
Also through is bantamweight John Joe Nevin who saw off Selcuk Exer of Turkey on a unanimous decision.
Fellow Olympian Adan Nolan is out after losing to Ukraine's Boghdan Shelestyuk.
Ok people JJ Nevin was spot on and gave a perfect performance 30-27 alll judgesAdam was hard done by 30-27 all judges @rtenews— Kenneth Egan (@kenegan30) June 4, 2013
Irish squad 2013 European Championships
49kg – Light flyweight – Paddy Barnes (Holy Family BC, Belfast)
52kg – Flyweight – Michael Conlan (St John Bosco BC, Belfast) WIN
56kg – Bantamweight – John Joe Nevin (Cavan BC)
60kg – Lightweight – Sean McComb (Holy Trinity BC, Belfast) OUT
64kg – Light welterweight – Ray Moylette (St Anne’s BC, Mayo) OUT
69kg – Welterweight – Adam Nolan (Bray BC, Co, Wicklow) OUT
75kg – Middleweight – Jason Quigley (Finn Valley BC, Donegal)
81kg – Light heavyweight – Joe Ward (Moate BC, Co. Westmeath) OUT
91kg – Heavyweight – Tommy McCarthy (Oliver Plunkett BC, Belfast)
91kg+ - Super heavyweight – Con Sheehan (Clonmel BC, Tipperary) OUT
Live web-only coverage of the semi-finals of the European Boxing Championships from 11.55 on Friday 7 June on RTÉ.ie (RoI only). Live web-only coverage of the finals of the European Boxing Championships from 11.55 on Saturday 8 June on RTÉ.ie (RoI only)
Live television semi-final action and highlights from 18:30 on Friday 7 June on RTÉ Two and RTÉ.ie (RoI only).