He was unhurt as the young terrorist lunged at his vehicle and detonated a bomb vest beneath school-style PE kit - designed to make him look like an innocent pupil out for a jog.
A terror cell linked to al-Qaeda is believed to be responsible for the assassination attempt in Noqm, a poor part of the city.
Three people - a passer-by and two security officials escorting the ambassador - were injured after the young man threw himself at the British convoy and triggered the bomb.
The terrorist was later identified as a 22-year-old high school student from the southern town of Taiz. His head was found on the roof of a house 20 yards away.
SMW knows what happens when people blow themselves up, but that last line still made my stomach lurch.