USA smashed the world record* in the women's distance medley with a time of 10:36.50 on the first day of the IAAF/BTC World Relays, Bahamas 2015.
The team of Treniere Moser (1200m), Sanya Richards-Ross (400m), Ajee Wilson (800m) and Shannon Rowbury (1600m) took more than six seconds off the previous mark of 10:42.57 that was set indoors earlier this year by a different US team.
The first leg looked to be more tactical in the beginning with none of the athletes willing to lead as the first lap was covered in just 69 seconds. But the pace had picked up by the end of the 1200m section, with France leading the USA, 3:18.11 to 3:18.38.
The slow first lap meant the teams were a few seconds outside world record pace, but a 50.12 clocking from Richards-Ross on the 400m leg put them back on course.
Wilson then ran a solo 2:00.08 for the 800m leg and Rowbury then increased their lead, which was already substantial, to bring the baton home in 10:36.50, covering the final four laps in 4:27.92.
In second, Kenya set an African record of 10:43.35 while Poland broke the European record with 10:45.32 in third place.
Another area record was set in fourth place with Australia clocking an Oceania best of 10:46.94.
Early leaders France faded as the race progressed and they eventually finished sixth behind Germany, both teams taking more than 11 minutes to cover the 10 laps.
Jon Mulkeen for the IAAF
*Subject to the usual ratification procedures.