Opemipo Jaji, 18, facing a life sentence after being found guilty of repeatedly raping the girl for three hours
Opemipo Jaji, an 18-year-old trainee chef, committed the rape after he had just left his probation officer when he spotted the girl going home from school on a bus last November.
After following her and forcing her into Jubilee Park in Enfield, north London, he attacked the girl, threatening to stab her if she resisted and telling her he would film her and send copies to children at her school and to "everyone you love".
After the rape, he went to a youth centre from which he had been banned as part of a supervision order.
In February 2011, Jaji sexually assaulted and robbed a 12-year-old schoolgirl on a housing estate. He was given a 10-month detention and training order in September 2011, serving five months in custody.
In April last year, he was fined £15 for failing to comply with the order, while a month later he was given a youth supervision order for 18 months for making indecent pictures of young girls.
A Probation Service spokesman said: "Our deepest sympathies are with the victim and their family following this horrific crime. A multi-agency public protection arrangement (Mappa) serious case review into what happened in this case has been launched."
Jaji, who was found guilty at the Old Bailey of rape , is facing a life term when sentenced on 7 June.
He had denied raping the girl, who gave evidence against him in court by videolink, claiming that he had been at a youth club working on a backing track for a song when the attack took place.
"I wrote the song after I heard a girl killed herself from bullying," he told the jury. "I wrote the song hoping things would get better." He said he had been on a bus with the schoolgirl and had picked up her travel pass when it fell to the floor.
Jaji said he went to Jubilee Park later that evening to compose music but left after 10 minutes because he saw police at the gate. Recalling the attack, his victim told jurors he had said he was "this close" to killing her.
She said: "He kept saying, 'Stop moving or I will stab you'. I tried to run away but then he grabbed me when I got to the pavement of the park entrance.
"I kept on saying 'stop' because it was hurting me and he kept saying 'shut up' to me. He was just saying it every time I spoke. When I was on the floor, he said he would film me and send it into my school. I was saying 'get off me, get off me, stop'."
The girl, who had one of her gloves stuffed in her mouth, ran home after she was allowed to dress.
Her parents were distraught when she turned up dirty and dishevelled, the court heard.
They had called police when she failed to arrive home from school by 5.30pm.The child was taken to hospital and underwent an operation.
Rosina Cottage QC, prosecuting, said: "Jaji is interested in little girls and sexual acts with little girls."
He was arrested a few days later after CCTV was examined and his bedroom was searched. A book was found about a little girl being sexually assaulted, along with advertisements for child-care vacancies and a picture of a young girl in Australia.
There was also an article about missing April Jones, the five-year-old Welsh girl thought to have been murdered.
Police believe he was a dangerous paedophile whose offending was escalating.
Detective Chief Inspector Adam Lowe of the Met's Sapphire command, said: "Jaji posed a great danger to young girls and despite the great weight of evidence against him, refused to accept his guilt and forced the victim to give evidence in court. This was a particularly brutal but unusual attack on an innocent 11-year-old schoolgirl who will no doubt continue to suffer the emotional scars of what happened to her for a very long time.
"I would like to take this opportunity to praise the bravery of the victim and her family."
Sarah Maclaren of the Crown Prosecution Service said: "This was a vicious and horrific attack on a young victim.
"As a result of this conviction a dangerous sexual offender has now been brought to justice.