Greta Streimikyte shaved almost four seconds off her lifetime best as she came home in fifth - later upgraded to fourth - in the Paralympics 1,500m final.
The 21-year-old Lithuanian-born runner set a new Irish record when qualifying for Saturday's final as one of the fastest losers.
She raised her game again, clocking 4.45.06 to come fifth, and then being bumped up to fourth after Mexico's Daniela Maldonado was disqualified.
"It's a championships, anything can happen," Streimikyte said afterwards.
"It was a massive experience. It motivates me to work even harder. Next year I'll be faster. It's a brilliant lesson and no medal can buy that. It's all good.
"My goal was to get a medal for Ireland. Unfortunately that didn't happen, but hopefully next time it will."
Greta Streimikyte has moved up to a fourth place finish following a DQ. She finished in a PB time of 4.45.06 pic.twitter.com/Q9zD3JINcq— Paralympics Ireland (@ParalympicsIRE) September 10, 2016
Streimikyte sat at the back of the group with world champion Somaya Bousaid of Tunisia setting the early pace alongside her team-mate Najah Chouaya.
They stormed at least 50 metres ahead of the rest with two laps to go, but Stremikyte regained contact with the next four back.
Streimikyte moved into fifth with a lap to go, as Bousaid streaked to gold, followed by Chouaya and then Ozes Ayucar of Spain.
Streimikyte did come home in fifth behind Maldonado, but the latter's disqualification made it an even sweeter day.
Orla Comerford finished fourth of five runners in heat 2 of the T13 100m - but that was enough to make Sunday's final as a fastest loser.
The Raheny Shamrocks sprinter clocked a PB of 12.81 to squeak through and will go to the blocks at 3.0 tomorrow afternoon dreaming of a podium finish.
"I was a little bit disappointed with the time, but I'm delighted I made a final, that was my aim," the teenager, who turns 19 on Wednesday, told RTÉ Sport.
"Hopefully I can run a little faster tomorrow!"