The boy, who cannot be named, lured the girl to his home where he threatened her with a knife and rape her.
The young woman, who has lifelong anonymity, bravely came forward after the attack in November last year.
And the 17-year-old boy from Wirral has now been sentenced to five years in prison over the attack.
He was sentenced to five years in a Young Offenders Institute and given an eight-year Sexual Harm Prevention Order at Liverpool Crown Court.
The Officer in Charge of the investigation, Detective Constable Barry Woodbridge said: “This was a particularly horrendous attack as the teenage offender lured the vulnerable child into his home address.
“The young victim was extremely brave to come forward and assist the police. I would like to praise the courage and dignity she has shown throughout the investigation.
“This sentencing shows that violence against women and girls will simply not be tolerated, and we will work tirelessly to bring perpetrators to justice.”
Specially Trained Officer Jessica Graham, added: “We have specialist officers who are dedicated to investigating these crimes, bringing those responsible before the courts and ultimately protecting young people from unimaginable suffering.
“Finally, I would like to take this opportunity to stress that if you have experienced any form of sexual abuse, or know of a child being abused, please come forward and report this to police.
“We take all such reports extremely seriously and if you can find the courage to come forward and speak to us we have specially trained officers who will treat you with sensitivity and compassion.”
If you’ve been affected by sexual violence, you can contact Childline – call 0800 1111.