Ireland's Daniel Wiffen won his second heat of the week, setting a new national record in the process with a time of 15:07.69 in the 1500m freestyle.

The Down swimmer smashed his previous Irish record by a whopping nine seconds but it wasn't enough to qualify him for the final.

The four heats in the 1500m freestyle are now concluded with the eight fastest swimmers advancing to the final.

Wiffen's swim, while enough to win his heat by the length of the pool, only landed him in 20th spot overall.

Afterwards, Wiffen said he was "over the moon" with his performance though admitted it was difficult when competing in a race which was effectively a time-trial, saying he expected "more of a race."

"I would have liked to be a bit faster but we can't ask for much more than a PB. Happy to improve my record by just under 10 seconds.

"I was expecting more a race to be honest. I know at my trials, I did it by myself so I had some practice before coming here. It's just hard doing it by yourself."

Nonetheless, the race caps an excellent debut Olympics for Wiffen, with national records at both 800m and 1500m freestyle and 14th and 20th place finishes respectively.

Earlier, Larne's Danielle Hill finished in 6th place in her 50m freestyle heat in a time of 25.70, outside her personal best.

The 21-year-old will not proceed to the final. On Sunday, Hill finished third in her 100m backstroke heat, finishing 21st and just missing out on the semi-final.

Hill after her 50m freestyle heat in Tokyo

Afterwards, an emotional Hill spoke of her difficult build-up to the Games but also of her pride of being an Olympian.

"I've been so caught up in the emotions of swimming and what happened beforehand that I don't think I've fully enjoyed the experience. But then again, it hasn't been a full Olympic experience.

"I think I'll step out of this Olympic bubble and I'll look back and be really proud I've stood here, competing against the best in the world.

"For now, I'm disappointed. But hopefully things will change when I see family and friends."

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