Americans Regan Smith, Lilly King, Kelsey Dahlia and Simone Manuel finished the race with a time of just 3 minutes 50.40 seconds, setting a world record.
In the lead-off leg, Smith set a backstroke world record of 57.57 seconds.
This feels like a Mary T situation - “Regan Smith Breaks 100 Backstroke World Record in 57.57 on 400 Medley Lead-Off” https://t.co/Fnk2KaMGaA— Mel Stewart (@goldmedalmel) July 28, 2019
The second-best team was Australia (-3.02 seconds); the Canadian team took third place.
The ladies broke a world record set by another US team (3.51,55).