PARIS (AFP) – Kaylee McKeown won back-to-back gold in the women's 100m backstroke while Daniel Wiffen made history as he became the first Irishman to win a swimming gold as he swept to victory in the 800m freestyle at the Paris Games on Tuesday.
There was also joy for Great Britain's men who defended their 4x200m freestyle relay gold with a convincing victory.
Australia's women continued their domination over their American rivals in La Defense Arena with McKeown beating world record holder Regan Smith in one of the most highly anticipated duels of the Games.
After Ariarne Titmus beat Katie Ledecky in the 400m freestyle 'Race of the Century' on the opening night and Mollie O'Callaghan won the 200m freestyle and the Dolphins combined for gold in the 4x100m freestyle relay, this was another show of strength.
"It's been an awesome few days watching all the Aussies get up and race so I just had to put my best foot forward tonight," said McKeown, who now owns four Olympic golds and will aim for another in the 200m backstroke.
"To have all this atmosphere all that adrenaline and be able to perform like that it's really special to me and I'm happy with have gone so far," she said.
She is now one of only two women, along with American Natalie Coughlin, to have won two golds in this event.
Smith, coached by Bob Bowman, Michael Phelps's former coach who is also working with French sensation Leon Marchand, had raised hopes last month of a gold by smashing the world record time, set by McKeown, in the US trials.
At the 50-metre mark, Smith was in the lead with McKeown trailing in fourth but, not for the first time, the Australian turned on the turbo power for the last 30m to win with an Olympic record time of 57.33sec with Smith 0.33sec behind.
"Ultimately, I think other people's performances are completely out of my control and Kaylee is... one on one, she is an absolutely incredible racer and she knows what to do when it matters, but I'm really proud of myself," said the American.
Katharine Berkoff of the United States, who had threatened an upset, had to settle for bronze.
Wiffen had talked ahead of his final of how he would be happy with any medal, especially given that Ireland had never had any kind of podium finish in men's swimming.
'I DON'T NORMALLY CRY'
But he delivered an epic finish to leave Tokyo champion Bobby Finke in second and experienced Italian Gregorio Paltrinieri with bronze as he set a new Olympic record time of 7:38.19.
Ireland's only swimming medals had come in 1996 in Atlanta when Michelle Smith claimed three golds, so it was no surprise that a tearful Wiffen was caught up in the emotion of the occasion.
"I don't normally cry, so I really hope that nobody's going to see that. But it did come out of me, and it's obviously just a special moment. I've never heard that national anthem at Olympics before, and, it's just crazy that it was me standing on a number one podium here for the first time at Olympics," he said.
Wiffen will swim in the 1,500m and he also plans to take part in the 10km open water race in the River Seine.
Duncan Scott delivered the clutch anchor leg for Great Britain as they held off the USA and Australia in the 4x200m freestyle relay.
Led off by James Guy and brought home by Scott, with Tom Dean and Matt Richards in the middle legs, they led from start to finish and touched in 6min 59.43sec.
The same team won gold at the Tokyo Games, which bettered the silver they claimed at Rio in 2016.
There was a shock in the heats when world record holder Qin Haiyang of China failed to qualify for the final of the men's 200m breaststroke.
Qin, the 2023 world champion in the event, was considered one of the favourites for gold but finished with a time of 2:09.96 in his semi-final, 1.85sec behind the fastest qualifier Leon Marchand of France.
That time, over four seconds slower than his world record mark, left Qin tied for tenth with American Matt Fallon.
Qin was reportedly among 23 Chinese swimmers who failed doping tests before the Tokyo Games but were cleared by Chinese authorities.
He and the Chinese authorities have denied any wrongdoing and stated that the swimmers had consumed contaminated food at a hotel where they were staying.