Magheralin native Daniel Wiffen has smashed the Irish national record to win his heat in the men's 800m freestyle.
His stunning time of 7:51.65 was good enough to finish 0.42 seconds ahead of the chasing Venezuela's Alfonso Mestre.
Sadly it still wasn't good enough to qualify as he ranked 14th overall with only the eight fastest swimmers from the five heats qualifying for the final.
He was just under four seconds outside the key eighth spot.
Wiffen's previous PB was 7:52:68.
The race didn't start well for the Team Ireland man as he found himself in seventh place for the first 200m.
He began shifting through the gears as he edged past the pack in the last 50m.
Wiffen is back in action again as the distance swimmer takes part in the Men's 1500m Freestyle heats on Friday at 11.48am UK time.
His record breaking attempt comes as fellow Team Ireland athlete Mona McSharry made history as she became the first Irish swimmer to make a final in 25 years.
She came came eighth in the 100m breaststroke final in a time of 1:06.94 at the Tokyo Aquatics Centre.
“It’s amazing," beamed McSharry, who was ranked 11 before the Games.
"When you think about it like that, 25 years and there hasn’t been anyone else, I think it puts it into perspective.
"Racing in it, it’s just another final but it really is a lot more than that. It’s really nice to hear that and just makes me feel so proud that I made it there."
"It definitely felt like a good race - and anything sub 1:07 is a good race in my mind, so I’m happy with the race."
