Mona McSharry finished fifth in the 100m breaststroke final at the World Aquatics Championships in Doha.
McSharry, second quickest in qualifying, was looking to become the first Irish swimmer to medal at a worlds but finished off the podium in a time of 1:06.42, just over a second behind Chinese gold medal winner Qianting Chang (1:05.27).
The Sligo swimmer's time was outside her semi-final time of 1:06.11, which would not have been enough for the podium in a final swam in little over a second outside world record time.
Second was Tes Schouten of the Netherlands in 1:05.82, with Siobhan Haughey of Hong Kong taking bronze in 1:05.92.
Haughey is the grandniece of former Taoiseach Charles Haughey.
"I'm gutted, I just felt like I was there, within my reach, I just didn’t have it today and that’s really tough to deal with, just back to the drawing board and keep working I guess," said McSharry after the race.
"I think, the most important thing is not coming away from this distraught or disheartened, and trying to use it to my advantage rather than thinking I’m not capable, and that’s probably going to be the hardest part."
McSharry returns to the pool on Thursday for the heats of the 200m Breaststroke where she will be seeking to secure an Olympic Qualification Time of 2:23.91.
Daniel Wiffen (above) comfortably advanced to 800m freestyle final at the World Aquatics Championships, but there was disappointment for Darragh Greene and Victoria Catterson in Doha.
Wiffen, who quickly turned his attention to the 800m after finishing seventh in Sunday's 400m freestyle final, progressed with a time of seven minutes 46.90 seconds as he finished second to Italian Luca de Tullio in the second fastest time across the heats.
Defending champion Ahmed Hafnaoui surprisingly failed to advance with the Tunisian only 18th fastest in a time of 7:51.52 seconds more than 14 seconds off his championship-winning swim at Fukuoka last July.
The final takes place on Wednesday.
Wiffen said: "I'm looking forward to it, getting into my preferred schedule now, the 800m and 1500m, so yeah I’m looking forward to it. It’s going to be a great race."
Greene was the first Irish swimmer in action today in the 50m breaststroke. His heat time of 27.76 placed him 18th overall and was not enough to advance.
Catterson pushed the Irish national record close in the 200m freestyle, but it wasn’t enough to see her through.
The 22-year-old was sixth in her heat with a time of 1:59.75 and 19th overall.
