Russia's Olesya Zykina shaded the closest women's World indoor 400m final in history to deny her compatriot Natalya Nazarova a third title in an exhilarating two-lap clash.
Just 0.01 separated the duo as Zykina matched her world leading time of 51.09 to guarantee a fourth successive gold medal in the event for the all conquering Russians.
Zykina and Nazarova were always heavily fancied to dominate but after an even start between the six finalists it was the American champion Shareese Woods, from lane three, who was the first to make an impression running down Ukranian Antonina Yefremova on her immediate outside.
By the time the athletes broke out of their lanes, however, the ginger-haired Zykina held a clear three metres advantage with Nazarova a stride ahead of Woods. Zykina posting 23.73 at halfway.
Down the back stretch Zykina's lead on her fellow Russian remained constant but as the long-time leader started to pay for her early pace Nazarova edged back into contention on the final bend.
Hitting the home straight Nazarova, the gold medallist at the 2003 and 2004 World Indoor Championships, was gaining with every stride on the outside of Zykina. But try as she might she simply just ran out of track. In a desperate lunge for the line it was Zykina who just held on to clinch victory by 0.01.
Behind the Russian duo Woods and Yefremova were locked in a private battle for bronze. But it was Woods who had just enough strength to hold on to to the bottom rung of the podium, setting a new personal best of 51.41. Yefremova also recorded her fastest ever indoor time with 51.53.
Somewhat surprisingly, Woods secured the USA's first medal in the event for 11 years since Jearl Miles Clark struck gold in the 1997 edition held in Paris.
Steve Landells for the IAAF