Annalise Murphy will not repeat her Rio 2016 heroics after missing out on the Laser Radial medal race.
The silver medallist from four years ago came into today's final two races in 14th, having made up ground after a slow start to the week.
However, Murphy was unable to force her way into the top 10, with finishes of 30th place (after a penalty turn) and 40th meaning the Dubliner finished in 18th overall after 10 races.
"I was having a difficult first race but I made a really good comeback," Murphy told RTÉ Sport afterwards.
"Then about halfway down the last downwind I got a yellow flag so I had to do a penalty. That dropped me back 10 or 15 place so that was tough to take.
"The second race I just held back too much on the start line. I guess I was quite sad going around. The last race of the Olympics, you want it to be a highlight, not a lowlight, but I'm really proud of how I managed to come back this week."
The 31-year-old said that light winds today made it difficult for her to make an impression.
"I was hoping we were going to get more conditions like yesterday, I knew that I would excel in those kind of conditions and I'm really glad we managed to get one day of it to show I can still be the best when the day comes around.
"It's always hard for me when it's light (winds) like that because I'm one of the bigger girls in the fleet.
"I'm always having to work so hard on trying to be lighter than my natural body weight.
"I have a little voice in my head saying 'light winds, it's going to be difficult for you' but I'm pretty happy I don't have to live off salad anymore!"
'I can't see myself going to another Olympics'— RTÉ Sport (@RTEsport) July 30, 2021
An emotional @Annalise_Murphy chats to @joestack_ky as she contemplates bringing the curtain down on her #sailing career#olympics #tokyo2020 #RTESport
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Murphy said she was "looking forward to a normal life" after over 12 years spent obsessively chasing her dreams and that she "can't see myself going for another Olympics".
"Aoife (Hopkins) and Eve (McMahon) are both going to be contenders in three years' time and I want to help them out. I hope I can give them some of my knowledge and maybe they can surpass all of my achievements. That would the dream, that I have left some legacy behind.
"I'm proud of myself for managing to make it to three Olympics. I came here thinking this was my chance to win a gold medal but it wasn't.
"But I've managed to win races at all three Olympics I've gone to so that's pretty good."
Denmark's Anne-Marie Rindom looked on course for gold but a bump with a competitor and her confusion over the rules saw her lead drastically cut ahead of Sunday's medal race.
Rindom, who took bronze at the Rio Games in 2016, was disqualified when she was shown a second yellow flag as her dinghy touched that of Dutch racer and nearest rival Marit Bouwmeester.
The Dane thought she was entitled to continue when a general restart was announced but, uncertain of the rules, she subsequently pulled out of the race for fear of being disqualified from the whole competition.
That resulted in 45 points being added to her total in a sport where the lowest score wins.
As a result, her 26 point-lead over second-placed Bouwmeester going into the final qualifying race ahead of Sunday's medal decider has been cut to seven points, with Sweden's Josefin Olsson three points further back.