Irish flyweight Michael Conlan is guaranteed an Olympic bronze medal after winning his quarter-final bout against France's Nordine Oubaali.
The two men were tied at 12-12 going into the final round but Conlan found another gear to claim a 22-18 victory and move into the semi-finals.
Earlier in the day Paul Hession had failed to make it out of the heats of the 200 metres.
The 29-year-old finished fifth in 20.69secs in a race won at a canter by Jamaican Yohan Blake.
Hession, who was 0.17s off the third spot he needed to progress, said: "It is a little bit disappointing.
"I was hoping to push closer to third or second in that race. There were some serious athletes in there. That doesn't mean I couldn't beat them, but it wasn't there.
"I was a metre away from where I needed to be to qualify."
Team-mate Fionnuala Britton ran a personal best of 15:12.97 in the heats of the 5,000m, but it was not enough to go through as she finished 10th.
Gavin Noble finished 23rd in the triathlon as he finished in a time of 1:49:47, 3:22 behind winner Alistair Brownlee.
In the men's 470 off Weymouth, Scott Flanigan and Ger Owens finished 16th and fifth in races nine and 10 to sit 23rd overall.