Maryam Jamal of Bahrain retained her title despite crossing the line in second place during a confrontational not to mention controversial final which was packed full of incident.
Spain's Natalia Rodriguez crossed the line first in 4:03.37 but was quickly disqualified from the race after elbowing Ethiopia's long-time leader Gelete Burka to the floor with 200m remaining.
The Spanish record holder raced across to Burka, who finished the race in 11th, to console her but her rather muted celebrations hinted at her guilt and sure enough the officials wanted to look into the incident.
She was duly disqualified and Jamal was promoted to the gold medal to became the second athlete in the history of this World Championships event to land back-to-back titles.
Great Britain's Lisa Dobriskey, who initially thought she had won bronze, was upgraded to the silver medal in 4:03.75 - an agonising 0.01 behind Jamal.
The US champion Shannon Rowbury was promoted to the bronze medal position in 4:04.18 - to become the first US medallist in this event since Regina Jacobs landed silver ten years ago in Seville.
The race set off minus Morocco's Mariem Alaoui Selsouli who did not start and in what was a first lap characterised by the regular sight of elbows and arms clashing in the 11-strong field Burka, the World No.3, took them through 400m in 1:06.66.
By the time the Ethiopian had circled a second lap of the race Burka had taken the field through in a modest 2:15.13 - a stride ahead of Russia's Natalya Evdokimova, Nuria Fernandez of Spain and Jamal.
It was at this point of the race Burka then pressed on the gas in an effort to draw the sting out of the opposition with Jamal the pre-race favourite taking close order.
At the bell the Ethiopian led from Jamal with Rodriguez third, Dobriskey, the Olympic fourth-placer, handily placed in fourth and Rowbury fifth.
Down the back stretch of the final lap however, Jamal started to eat into Burka's lead and the top five started to concertina. This led to the major race incident as Rodriguez found her way blocked by Burka on the inside and barged Burka - it has to be said with little subtlety to the floor.
The Spaniard was forced to step on to the infield and Dobriskey skipped out of the way of the horizontal Burka.
Coming into the home straight Jamal held a slight advantage from Rodriguez with Dobriskey on the outside. It was the Spanish athlete, though, who powered home to cross the line first.
Yet the officials not unsurprisingly disqualified Rodriguez and it was Jamal by just 0.01 - who took gold in 4:03.74. Probably not caring one bit that she had just recorded the second slowest winning time in the history of this event at the World Championships.
Rodriguez's Spanish team-mate moved up to fourth in 4:04.91 with Wurth-Thomas of the USA fifth in 4:05.21. Her team-mate Anna Willard placed sixth to ensure the US had three finishers in the top six.
Burka dragged her body off the floor like a boxer who had been knocked to the canvas to finish 11th in 4:11.21. She was consoled by a guilty looking Rodriguez after the race but Burka did not appear to acknowledge the Spaniard and lay on the track in a state of some distress.
Steve Landells for the IAAF