USA’s Francena McCorory lived up expectations as the favourite, speeding to a popular victory in 51.12.
The 25-year-old member of the USA’s victorious London 2012 Olympic Games 4x400m team made up for placing only sixth in the 2013 IAAF World Championships in Moscow last summer by claiming her first major championship individual honour.
The fastest woman of 2014 with a 50.85 clocking, set at attitude when winning the US title in Albuquerque last month, McCorory bided her time in fourth position at the bell before unleashing an almighty kick with 150m remaining to overtake her rivals.
Jamaica’s Kaliese Spencer, better known as a hurdler, sprinted to a 51.54 lifetime best and the silver medal, as The Bahamas’ former world junior and world youth champion Shaunae Miller collected the bronze with 52.06.
The teenage Miller, still 19, led the field until the halfway point but didn’t quite have the strength to hold off the more experienced McCorory and Spencer and faded in the closing stages.
Polish hearts were broken as Justyna Swiety had to settle for fourth place in 52.20.
Nicola Bamford for the IAAF