After the ups and downs in the hours leading up to the event, Kathleen Ledecky of the United States became the first Olympic gold medallist in the women's 1500m freestyle after winning in a time of 15:37.34 here on Wednesday morning.
Kathleen's teammate Erica Sullivan claimed silver in 15:41.41. Sarah Kohler took bronze for Germany in 15:42.91. Wang Jianjiahe of China ranked fourth with 15:46.37.
"I'm so happy to go one-two with Erica. It is the first women's 1500m (freestyle in Olympic history) so I couldn't have a better outcome than that. I'm so, so happy," said Kathleen, reports Xinhua.
Earlier in the morning on Wednesday, Kathleen failed to continue her gold-winning streak in the women's 200m freestyle by ranking fifth.
"After the 200m, I knew I had to turn the page very quickly and in the warm-down pool I was just thinking of my family. Each stroke I was thinking of my grandparents. They're the toughest four people I know and that's what helped me get through that," Kathleen replied on her emotions after crying with joy in the pool.
Before its debut in the Olympic programme in Tokyo, the women's 1500m freestyle has featured at the world championships since 2001. The current world record holder Katie Ledecky has won the most world titles in this event, taking gold in 2013, 2015 and 2017. She withdrew because of illness in 2019.
Ariarne Titmus won the gold for Australia in the women's 200m freestyle, setting a new Olympic record at 1:53.50. Australia has won three gold medals in the women's 200m freestyle at the Olympic Games -- in 1972, 2000 and Tokyo 2020.
Siobhan Bernadette Haughey clinched silver as the first ever Olympic swimming medal for Hong Kong. Penny Oleksiak took bronze for Canada.
"I'm really happy and really excited. I worked hard for this for the last five years. The medal means so much," Haughey said about her silver.
Yui Ohashi won the women's 200m individual medley gold for Japan in 2:08.52. Ohashi had won the women's 400m individual medley on July 25, becoming the first Japanese woman to win two gold medals at a single Olympic Games, also the first Japanese woman to win two Olympic gold medals in swimming.
Alex Walsh claimed silver for United States, with teammate Kate Douglas took bronze. World record holder Katinka Hosszu only ranked seventh with 2:12.38.
Britain won its first Olympic gold medal in the men's 4x200m freestyle relay with 6:58.58. The Russian Olympic Committee team and Australia took the silver (7:01.81) and the bronze (7:01.84) respectively.
Britain were world champions in the men's 4x200m freestyle relay in 2015 and 2017, and now recorded their first Olympic gold in the event.
Kristof Milak of Hungary added an Olympic gold to his world title and world record in the men's 200m butterfly, after hitting a time of 1:51.25 to post a new Olympic record.
"My suit tore 10 minutes before the start of the race, just before entering the call room. At that moment I knew that the world record was gone, because I was totally off focus," said Milak.
Milak won the men's 200m butterfly at the world championships in 2019 in a world record time of 1:50.73, becoming the first and so far the only person to go under one minute and 51 seconds.
Tomoru Honda won Japan a silver at 1:53.75, while the bronze went to Italy's Federico Burdisso at 1:54.45.