Annalise Murphy made a strong start to her Olympic mission with a first and 14th in the opening two Women's Laser Radial Class races on Monday.
The Irish sailor ended the day in fourth place, but was later bumped up to third in the overall standings after China's Xu Lijia was disqualified from race 2 for an infringement.
Xu won gold in London four years ago and bronze in Beijing back in 2008.
Murphy ended up just outside the medals at the London Games, despite heading the standings from the start until the final three races, and is desperate to banish the demons of her agonising fourth-placed finish in 2012.
It was a devastating near-miss, but the Dubliner hit the ground running with a strong opening display in the first race. She was seventh after the first marker, before sitting just behind Xu.
"I am going to be looking at the mistakes I made - I didn't sail perfectly at all." - Annalise Murphy
Murphy hit the front after the third marker and stayed there, winning in 50:57. She returned later in the evening to carve out a 14th-placed finish in the second of ten races, before a final medal race decides who makes the podium.
Murphy now has 15 points, just one more than Denmark's Anne-Marie Rindom, who is in bronze medal position. Xu leads the fleet with seven points.
"It was fun," Murphy said. "It was really tricky. It's really up and down, pressure differences across the course and a strong tide playing a big part in it.
"I had two bad starts so I had to fight back from there, but I am happy enough with today.
"I am going to be looking at the mistakes I made - I didn't sail perfectly at all. I can definitely improve things.
"I am just going to look at that and forget about today because every day here with the different race courses will be completely different.
"You can't look at one day and think it'll be the same the next day because it's not."
Annalise Murphy has finished 14th in Race Two and ends the first day in fourth position overall #rterio2016 pic.twitter.com/qRLVP5sxcS
— RTÉ Sport (@RTEsport) August 8, 2016
Finn Lynch finished 14th in race 1 of the Men's Laser Class, and followed that up with 28th in race 2 to lie in 21st overall.
The Carlow native pulled back from 27th in the middle stages of the opener to finish two minutes and 20 seconds behind the leader. Lynch fell back down the filed in the follow-up but he will be content with a solid start.
The 20-year-old is the youngest member of Ireland's sailing team.
He was tagged as one for the future but such has been the speed of Lynch's progress, he now finds himself on the biggest stage of all and acquitted himself excellently in his first outing.
Good start Finn Lynch - The 20 year old is 21st of 46 after 2/10 races in Men's Laser Class #Sailing #TeamIreland pic.twitter.com/26tlopRbG3
— Team Ireland (@olympiccouncil) August 8, 2016
