PIX: McKeown extends reign, Wiffen toast of Ireland

Australian dominator Kaylee McKeown crushed Regan Smith to extend her reign over the 100 metres backstroke before Irish trailblazer Daniel Wiffen became his nation's first man to win an Olympic swimming medal with 800m freestyle gold on Tuesday.

Great Britain capped the night session on day four by defending their men's 4x200 metres freestyle relay crown at a heaving La Defense Arena.

Britain's late triumph was their first gold medal of the Paris swimming meet and condemned the United States to a second straight day without a title.

Instead, Americans had to settle for minor medals in all three events as Australia extended their lead at the top of the table with four titles to the U.S. team's two.

Three years after driving Australia to a record haul of nine gold medals at Tokyo, the nation's brilliant women have again done all the heavy lifting.

Backstroke queen McKeown may well end up the best of the lot, having stared down American rival Regan Smith, the would-be challenger who snatched her World record weeks before the Games.

McKeown's strong back-end pace made the difference again as she mowed down eventual silver medallist Smith and American bronze-winner Katharine Berkoff to retain her own 100m title in an Olympic record time of 57.33 seconds.

She joins teammate Titmus and swimming icons, Ian Thorpe and Dawn Fraser, among Australians with three individual gold medals.

"It feels pretty cool. It's great to be a part of history. Hopefully I can keep the momentum going for the rest of the week," said the 23-year-old, her nation's first woman to win a backstroke title.

The Ireland team have been buzzing since Mona McSharry took a surprise bronze in the women's 100m breaststroke on Monday, and the lanky Wiffen ramped up the party several notches with an emphatic win for the 800m freestyle title.

The 23-year-old clocked an Olympic record time of seven minutes 38.19 seconds to dethrone American champion Bobby Finke, who took silver.

Italy's Gregorio Paltrinieri took bronze three years after being runner-up at Tokyo.

Already Ireland's first World Championship medallist in swimming, Wiffen wiped tears from his eyes on the podium after breaking new ground in the Olympic pool and securing the country's first gold at Paris.

In the 4x200m freestyle relay the quartet of James Guy, Tom Dean, Matthew Richards and Duncan Scott then kept the gold medal in British hands, beating the Americans by 1.35 seconds, with Australia taking the bronze.

It came three years after the same British foursome beat a Russian team and Australia for the title in Tokyo.

Scott's gold was a record seventh Olympic medal -- two golds and five silvers -- for a British swimmer and there was no catching him on the last leg.

Scott and Guy also took silver in the event at Rio 2016.

• THE OLYMPICS, 2024