Irish lightweight Sean McComb progressed to the last 16 on a unanimous decision in Baku.
McComb beat Ukraine's Tymur Beliak 29-28, 30-27, 29-28 after splitting the judges in his favour in the first and third rounds and taking the second unanimously.
The Irish elite champion will now meet Italy's World Series of Boxing fighter Donato Cosenza tomorrow for a place in the quarter-finals.
Cosenza was TKOd in the second by Ireland's David Oliver Joyce in the Chemistry Cup in Germany last year and also lost to Joyce in an Olympic test event in London in 2011.
Irish head coach Billy Walsh expressed surprise that McComb didn't win the first round against Beliak on all three judges' cards.
"We thought that Sean won the first round unanimously, His opponent didn't touch him. It was a superb performance, probably our best of the tournament so far," said Walsh.
The remaining 11 Irish boxers will be in action today, tomorrow and Sunday, with Katie Taylor slated to meet Bulgaria's Denista Eliseeva for an eighth time on Sunday.
Taylor has beaten Eliseeva on six occasions, amassing 69 points and conceding 20 under the old computer scoring system. She has also beaten the Bulgarian under AIBA 10-point must scoring.
However, Eliseeva was controversially awarded a 5-1 decision over Taylor at the Strandja Memorial in Bulgaria in 2011, the last time the Bray lightweight was beaten.