Paul O'Donovan and Fintan McCarthy began their quest for another gold medal as they eased through their Men's Lightweight Double Sculls heat.
The Skibereen duo finished first ahead of Norway and Greece to book their place in the semi-finals.
Elsewhere this morning, Fiona Murtagh and Aifric Keogh took second in the women's coxless pair with a time of 7:28:22 to make their semi final.
Margaret Cremen and Aoife Casey took third place and a place in the repechage in their Women's Lightweight Double Sculls heat.
In the men's coxless pair, Ross Corrigan and Nick Timoney took third to pip world champions Switzerland to qualify for their semi with a time of 6:32:34.
Emily Hegarty, Natalie Long, Eimear Lambe and Imogen Magner were drawn in a tough heat in the Women's coxless four, but have qualified for the Tuesday repechage as they finished in third spot this morning.
In the pool, Mona McSharry finished second in her Women's 100m Breaststroke heat with a time of 1-minute 5 to qualify for the semi-final.
However in the boxing ring, Aidan Walsh has suffered defeat to hometown favourite Frenchman Makan Traore in their 71kg clash.
Walsh took the opening round but was rocked in the third round, and could not recover.
Later today, Grainne Walsh goes in her 66kg clash with Anna Luca Mamori of Hungary at 4.30pm.
And Jack Marley begins his Olympic quest, taking on pr: (Mat-ay-ushz Behr-ez-nik-ee) Mateusz Bereznicki from Poland in a 92kg clash at 7.15pm.
The women's rugby sevens will look to start strongly when they take on Team GB in the first match of their group stage at half 2.
Meanwhile sailors Robert Dickson and Sean Waddilove are involved in the Men's Skiff event this afternoon.
Dubliner Nhat Nguyen has beaten Misha Zilberman of Israel by 2 games to 1 in his first group match in the men’s badminton.
And gymnast Rhys McClenaghan breezed into the pommel horse final with a near flawless qualifying score of 15.200
===
Elsewhere at the games,
Canada women's manager Bev Priestman has been banned from football for a year following a spying row.
The country's Games chief David Shoemaker revealed yesterday it was "highly likely" she knew a drone was used to snoop on opponents' New Zealand's training session.
The side have also been docked 6 points in this year's competition which makes their title defence a huge uphill task.
Meanwhile, Antoine Dupont lead from the front as France took gold in the Rugby Sevens event.
