Summer McIntosh led from start to finish to win her fourth gold at the Singapore world championships on Sunday with a dominant victory in the 400m individual medley.
The 18-year-old Canadian phenomenon romped to victory in a championships-record 4min 25.78sec, with Australia's Jenna Forrester and Japan's Mio Narita sharing silver (4:33.26).
China's 12-year-old Yu Zidi was narrowly out of the medals in fourth in 4:33.76.
World record-holder McIntosh was red-hot favourite beforehand and she was never in trouble as she added to her Singapore triumphs in the 200m medley, 200m butterfly and 400m freestyle.
McIntosh's only defeat of the championships came on Saturday when she finished third in the 800m freestyle, with Katie Ledecky dominating that event once more.
McIntosh won three golds, including in both individual medley events, at the Paris Olympics a year ago.
She came to Singapore in superb form, having broken three world records in a matter of days in the Canadian trials, including in the 400 medley (4:23.65).
Along with McIntosh, Yu has been one of the names of the competition.
Huge cheers went up for her from the large number of Chinese fans as she entered the arena for the final on Sunday, the last day of competition.
Yu this week became the youngest swimmer in history to win a world championships medal with bronze in the women's 4x200m freestyle relay.
She came fourth in all three of her individual races.
But not everyone thinks Yu should be competing in Singapore.
Some in the sport have raised questions about the mental and physical impacts of high-level training and competing at an age when she is still developing as a person.
Under current World Aquatics rules, the minimum age is 14 but younger swimmers can compete at the championships if – like Yu – they are fast enough.
