The quartet of Regan Smith, Lilly King, Kelsi Dahlia and Simone Manuel helped the U.S. better their own world record of 3:51.55 en route to the 2017 world title in Budapest, with a time of 3:50.40
In the lead-off leg, Smith also set a backstroke world record of 57.57 seconds, to break the existing record set by Missy Franklin in 2012.
World Championships
'Embarrassed' Australia defend concealing Jack's positive test
28/07/2019 AT 03:03
Australia (3:53.42) took silver, while Canada (3:53.58) took bronze.
World Championships
Peaty clinches seventh world title with 50m breaststroke gold
24/07/2019 AT 14:53
World Championships
Hungary's Milak breaks Phelps' 200 butterfly world record
24/07/2019 AT 12:10