The US swam a sneaky fast time in the 4x100 medley relay, leading start to finish by using an impressive front half highlighted by Lilly King's 1:04.93 split.
Qin breaks record for clean sweep as O Callaghan claims double mb.com.ph - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from mb.com.ph Daily Mail and Mail on Sunday newspapers.
John Mason, the announcer at the swimming world championships, stuck a nickname on Mollie O Callaghan after the 19-year-old Australian added the 100-meter freestyle title to her gold in the 200 two days earlier.