A 14-year-old boy was punched and had a can of beer poured over him while being robbed by two drunken men in Leicester's Abbey Park.
The muggers, Mustafa Raza Hanif (22) and Muhammed Ayub Osman (21), were caught after a patrolling police community support officer chanced upon the scene.
Both pleaded guilty to robbing the boy of two mobile phones, a house key and five pounds, on September 13.
Hanif and Osman, both of Earl Howe Street, Highfields, Leicester, were each jailed for two years.
The victim suffered a cut right ear, a cut nose and dizziness, the city's crown court was told.
Sentencing, Judge Simon Hammond said: "There was violence involved and the victim was a vulnerable 14-year-old boy.
"To pour beer over a young lad is a most demeaning, unpleasant and humiliating thing to do.
"He's now scared when he goes out that he'll be robbed.
"Offences like this often make people reluctant to go to parks in city centres, fearing they'll be robbed.
"The courts have a duty to protect the public from violent robbers."
Alan Murphy, prosecuting, said that at 5.30pm the victim was playing football on the park with two friends when the defendants, who were drinking cans of beer, approached them.
They started pushing the two friends around.
The victim intervened and was then surrounded by warehouse worker Hanif and unemployed Osman, as the two footballing friends left the scene.
Mr Murphy said: "The victim was led to a nearby tree where and told to sit on the ground.
"Osman sat next to him whilst Hanif demanded his mobile phones, telling him if he didn't hand them over he was going to be hit.
"The boy refused and Hanif punched him with his fist.
"He then took two mobile phones worth a total of £165, a key and five pounds.
"PCSO Richard Jones, who was on cycle patrol in the park, heard voices and a disturbance in some bushes.
"When he went towards that area he saw Osman aiming kicks at something or someone, but couldn't see what.
"The boy emerged shouting he'd been robbed and hit.
"The defendants, on seeing the officer, made off, but other officers arrested them nearby.
"When detained, Osman said he was going to co-operate and pointed to some bushes where one mobile phone and the house key were recovered.
"Hanif told the police he went to the park to drink, not just to commit a robbery."
The second phone and five pounds were never recovered.
Shital Modhwadia, mitigating for both defendants, said: "It's the first time they've been to a court.
"The offence was unplanned and opportunistic - and there's evidence of remorse because they readily cooperated with the police.
"Both men feel they've let their families down."
