Four-thousandths of a second. That was Christine Ohuruogu’s margin of victory on Monday night as she became world 400 metres champion for the second time in her career, breaking Kathy Cook’s 1984 British record in a stunning one-lap race.

Four-thousandths of a second. It is a period of time so miniscule it is almost impossible to comprehend. Yet even more improbable was the dramatic nature of Ohuruogu’s victory.