A cold-eyed Toby Carvery diner unleashed a random attack on a woman – while she was queuing for gravy.
Stunned staff were forced to intervene when Sarah Pritchard, 35, began grappling with mum-of-one Joanne Blanche, 50.
Ms Blanche was spooning gravy over her roast potatoes when a crazed Ms Pritchard grabbed her arm.
She said she has no idea why she was attacked – and hit out after Pritchard was fined £54 after admitting common assault.
Others diners ran for cover as Ms Pritchard grappled with the mother-of-one Mrs Blanche at the counter.
Prosecutor Rob Simkins said: "Mrs Blanche was at the gravy station when she was grabbed by the arm and assaulted.
"Restaurant staff intervened and the police were called – it was not what you expect in a family restaurant at lunchtime."
Police arrived at the Cedar Tree pub and restaurant in Caerphilly, South Wales, to arrest mother-of-three Pritchard.
No compensation order was made to Mrs Blanche who was left bruised by the attack just before Christmas.
Restaurant regular Mrs Blanche, of Trethomas, Caerphilly, said after the case: "It's normally a quiet and safe place, there's never any trouble.
"But I was at the gravy station when she suddenly grabbed me by the arm and started a fight.
"I don't know why she picked on me, I was minding my own business.
"A fine of just £54 isn't very much and won't stop her doing it to someone else in the future."