Australia's Mollie O'Callaghan stormed to victory in the women's 100 metres freestyle race at the World Aquatics Championships in Fukuoka on Friday, capturing gold in a time of 52.16 seconds to defend her title and complete a sprint sweep.
Australia had dominated the event with three titles in the previous five editions of the championships thanks to victories by O'Callaghan at Budapest in 2022, Bronte Campbell at Kazan in 2015 and Cate Campbell at Barcelona in 2013.
The 19-year-old O'Callaghan ensured that fine run continued by finishing strongly to edge out Siobhan Haughey of Hong Kong who grabbed silver in 52.49 seconds.
O'Callaghan also became the first woman to win the 100m and 200m titles at the same worlds.
Marrit Steenbergen of the Netherlands set the pace in the semi-finals but had to be content with bronze after coming home 0.55 seconds behind the winner.
South Africa's Tatjana Schoenmaker had set the benchmark in the women's 200m breaststroke with the quickest semi-final time and the 26-year-old will look to claim her first gold of this year's meet later after a silver over 100m earlier this week.
Looking to deny her will be Tes Schouten of the Netherlands and American Kate Douglass, with the top three separated by only 0.68 seconds ahead of the final.
American Ryan Murphy faces a tough task in his quest to retain his men's 200m backstroke crown, with the trio of Roman Mityukov, Benedek Bendeguz Kovacs and Hubert Kos all going faster than the 28-year-old in the semi-finals.
Victory for the experienced Murphy over his younger rivals will complete a superb double at Fukuoka, after he won the 100m backstroke title beating the fancied Thomas Ceccon of Italy.
Australia's Zac Stubblety-Cook is the overwhelming favourite to defend his men's 200m breaststroke title after solid displays in the preliminary races and the 24-year-old will aim to lower his own world record of 2:05.95 set in Adelaide last year.
His biggest challenger will be China's Qin Haiyang, who is looking for a third gold after wrapping up breaststroke titles over 50m and 100m at the Marine Messe Hall.
Qin was 0.43 seconds slower than Stubblety-Cook after the semis with American Matt Fallon a further 0.20 seconds away.
Australia will look to boost their gold medal tally further when their men's team take to the pool for the 4x200m freestyle relay with the US, Italy and Britain set to challenge in the day's final race.