A teenager spat on a conductor after a ticket row.
The then 16-year-old assaulted James Stewart who was working abord a train heading to Glasgow Central station on October 15, last year.
Mr Stewart approached the boy who handed him a ticket for elsewhere.
Prosecutor Jessica McGowan told Glasgow Sheriff Court: “The victim said that it was an invalid ticket.
"The boy became immediately aggressive and shouted 'It is a valid f***ing ticket, give me the f***ing ticket back'."
Mr Stewart told him to buy a ticket on board or at Glasgow Central station.
Around five minutes later, the lout again approached Mr Stewart.
He shouted: "Give the f***ing ticket back."
Mr Stewart told the boy to calm down.
Miss McGowan added: "The boy moved towards Mr Stewart and spat on his face.”
Police officers later arrested the boy as the train pulled into the station.
The first offender pleaded guilty to assaulting Mr Stewart Sentence was deferred pending background reports until next month by Sheriff Tony Kelly.
The now 17-year-old had his bail continued meantime.