Britain's Olympic champion Christine Ohurougu has beaten Amantle Montsho by just four thousandths of a second to win the 400m title in Moscow.
Ohurougu set a new British record time of 49.41 seconds on Monday to regain the word championship title she first won in 2007.
The 2008 Olympic champion, threw her body at the line to cap a great comeback and cross just in front of defending champion Montsho of Botswana as both were given the same time of 49.41 seconds.
Antonina Krivoshapka of Russia took bronze in 49.78.
Olympic champion Sanya Richards-Ross did not compete because of a toe injury.
"When I finished I didn't know if I'd won it, I didn't want to get over-excited until my name came up,'' Ohuruogu said.
"I heard everyone screaming and I looked up and I'm just so happy.''