Domino's Pizza has launched an investigation after one of its delivery drivers toppled over doing a motorcycle wheelie on a main road.
The stunt on Clapham High Street in south London was captured on video which was posted online, prompting one Twitter user to ask: "I wonder what state the pizzas were in?"
A spokeswoman for the pizza chain described the driver's antics as "wholly unacceptable".
Footage of the incident, which lasts about 12 seconds, shows the driver riding up the road on his back wheel with the sound of cheering in the background, which then turns to laughter when he loses his balance and falls over.
The clip shows two cars driving past him in the opposite direction, and ends with him bringing his motorcycle back to the upright position and appearing to take off on two wheels.
The Domino's spokeswoman said: "The safety of the public and of our colleagues is of paramount importance and this is clearly wholly unacceptable behaviour.
"We have launched an investigation to find the driver concerned and take appropriate action."