A two point penalty sustained in the first round proved decisive this afternoon as John Joe Joyce became the first Irish boxer to exit the Olympic Games. Earlier,Ireland captain Kenny Egan coasted into the light heavyweight quarter-final with a routine win over Turkish opponent Bahram Muzaffer at the Workers' Gymnasium.
Light welterweight Joyce was up against it from the start against Felix Diaz from the Dominican Republic and the early penalty cost him when the final score of 11-11 forced a countback.
Diaz set a ferocious pace from the off and rattled Joyce with three early clean shots. The 20-year-old scored with a right but was penalised immediately afterwards to trail 1-5 at the end of the first.
A body punch, a left jab and a solid right hand helped Joyce to a 3-2 win in the second and as Diaz took a breather in the third the Mullingar fighter edged into a 9-8 lead after winning the round 5-1.
Joyce looked to have the momentum despite a standing count in the last and coach Billie Walsh being sent from ringside. A late blow from Diaz, however, forced a countback and the judges ruled against the Irishman.
Egan was on top throughout and won by 10 points to two after four rounds, forcing a standing count for his opponent in the final round.
The Neilstown fighter will now meet Washington Silva in the last eight on Tuesday. If he beats the 32-year-old Brazilian he will be guaranteed a bronze medal.
His performance today was another assured one and means he has only conceded four points in his two bouts so far, while scoring 30.
Egan took control against Muzaffer in the second round. After winning the first 2-1, a quick right jab and then a solid left laid the foundation for a 4-1 lead.
The third was even more assured thanks to varied combinations and he quickly moved into a 9-2 lead ahead of the final round in which he boxed clever and allowed the tiring Turk chase him around the ring.
The eight-time national amateur champion looked happy with himself at the end and will be confident ahead of his meeting with Silva, who looked a spent force when edging past (9-7) Ghanaian Bastie Samir in the previous fight.
Britain's Billy Joe Saunders failed in his bid to get past world-class Cuban Carlos Banteaux in the welterweight second round earlier this morning and crashed out of Olympic competition.
The 18-year-old was well beaten 13-6 by his opponent who was never behind and exhibited a slick, counter-punching style which is expected to earn him the gold medal.
Saunders fell three points behind at the end of the first round but clawed his way back to level with some fine right hands, only for the Cuban to sneak back in front 5-4 at the half-way stage.
The Cuban's accuracy helped him rebuild his lead in the third round and as Saunders desperately chased the shots to haul himself back into contention, the favourite began to pull away.
Saunders said: "The points didn't go for me today. In the last round I knew I wouldn't get the decision unless I knocked him out. The scoring here is so bad for an Olympic Games. It's unbelievable.
"I felt my performance was exceptional, but I've had better days. I felt I should have had six or seven points for my body shots, but they're not scoring body shots. You might as well do fencing, not boxing, if they're going to do that."