Two grandmothers on mobility scooters had to be dragged apart after getting into a fight where they were "ramming each other like dodgems" in a supermarket.
The women were separated after they started trading blows in front of shoppers in an aisle of the Iceland store in Crawley, West Sussex.
They were prized apart after staff heard screams.
A store worker said: "It was shocking.
"Seeing these two old ladies going for each other like that was truly disturbing."
The shelf-stacker, who did not wish to be named, added: "They could have been seriously hurt - they were ramming each other like dodgems."
Cops were called to the scene after the warring pensioners - who were pals - fell out over money.
They arrested one of the pensioners, who has not been named, on suspicion of assaulting the other 78- year-old woman who suffered an injury to her arm. She was later taken to hospital.
The grand-daughter of one of them said: "The two of them met some months ago and this lady was always at grandma's house.
"They became really friendly but fell out massively over money."
It is not yet known whether charges will be brought.
It is not the first time mobility scooters have been used dangerously.In Rugby, Warwickshire, the policy introduced a speeding clampdown on mobility scooters, which can reach a top speed of 8mph, after a series of collisions and near misses in the town centre.