Great Britain's women's 4x400m relay team have qualified for tomorrow's night final inside the Olympic Stadium.
Cox got the team off to a good start during the opening leg and she eventually passed the baton to McConnell in second place.
However, the change between McConnell and Child was poor and the squad lost ground on the United States and Russia.
Ohuruogu steadied the situation on the final leg though as the Brits guided the baton around in a time of 3:25.05.
The USA won the race, while Russia ended up in second spot.