Alan Walker groomed the teenager while posing as a string of fake characters online.
He arranged to meet the schoolgirl in Musselburgh, East Lothian claiming to be a young man called Jamie.
But, the 37 year-old then dragged her into a field, blindfolded and battered her before raping his terrified victim.
The girl was already known to depraved Walker having previously met her for sex.
However, she was clueless he was the rapist having managed to keep his identity hidden.
Unaware he was the culprit, Walker was then the first person the hysterical teenager called for help shortly after her ordeal.
But, Walker was later held after a search of his laptop revealed grim details of his plans to attack the girl.
Today he was jailed for 10 years, with a five year extended sentence when he will be supervised in the community, after pleading guilty to a string of charges at the High Court in Glasgow including rape and grooming offences.
Judge Lord Turnbull told him: “As a mature adult you engaged in a sophisticated and carefully planned scheme which permitted you to trick and manipulate a young girl of only 14 at the time.”
The girl had initially been in regular contact last year via social media with a person she believed was called Jason Clarke.
This was Walker who had set up a fake Facebook profile along with photos he had scoured from the web.
It was during one online chat that “Jason” suggested the girl should meet “his brother” Alan Walker and “encouraged” her to have sex with him.
Prosecutor Shirley McKenna said: “He told her that he wanted to keep in his brother’s good books.
“Jason Clarke convinced her saying that he needed his brother to help him get a house...that he needed to keep him happy.”
The girl agreed to meet Walker and despite her revealing her age, he told her: “Oh well, just don’t tell anyone.”
The court heard Walker went on to repeatedly have sex with the underage girl at his home in Musselburgh between October and December last year.
In January this year, the girl turned up at Walker’s home to state she might be pregnant, but a test proved negative.
She told of plans to meet a “Jamie Smith”, who she had again been in contact with online.
But, this was also Walker, who had set up another bogus Facebook profile.
The chats with “Jamie Smith” were described as “sexually explicit”.
The court heard “Jamie” told the girl to meet him near playing fields in Musselburgh on January 11 and directed her how to get there.
The unwitting teenager later headed towards there and clocked who she thought was her online friend.
It was Walker – posing as “Jamie” - who had his hood up with a dark snood covering his face.
She was then dragged down into the field and had her underwear ripped.
Walker pinned the girl to the ground, who desperately tried to wriggle free. Miss McKenna added: “He slapped her on the right side of the face, striking her cheek and eye.
“He then wrapped a dark woollen snood around her head covering her eyes.”
Walker then went on to have sex with the frightened schoolgirl while also biting her on the back and shoulders.
The victim eventually managed to push away from her attacker and then fled the scene.
As the badly-beaten girl then looked for help, it was Walker she turned to first - oblivious he was the attacker.
Miss McKenna told the court: “When she met him, she was in tears and was unable to tell him what had happened until they got back to his home.
“She was hysterical and unable to say what had actually happened. She lifted up her top and showed her ripped underwear saying: ‘This might explain something’.”
Walker then insisted he would “do anything to get rid of Jamie Smith” - while also trying to persuade the victim not to go to police.
But, the teenager went on to tell her grandparents, who immediately dialled 999.
As police stepped up the hunt to catch the attacker, Walker was quizzed and told officers about his “friends” Jason Clark and Jamie Smith.
He also admitted having previously been in a sexual relationship with the girl.
Officers went on to carry out Facebook checks – and it was discovered the “Jamie Smith” profile had been accessed at Walker’s home on the day of the rape.
Chats between “Jamie” and the victim were then found on Walker’s laptop.
The fake Facebook pages for “Jason Clarke” and another bogus profile were also discovered.
Miss McKenna: “It would appear that he has created and managed these profiles in order to attract and contact this young girl.”
The prosecutor added: “Alan Walker has deliberately set up these fictitious characters and scenarios to deceive this young girl and the rape was clearly a planned attack.”
The court heard his DNA also linked him to the rape. Former friends and colleagues – including his ex-lover – identified Walker from CCTV close to the scene of the attack.
Walker had worked as a restaurant manager at a hotel in Aberlady, East Lothian, but has since been sacked.
The ordeal is said to have left the victim “damaged” and that her schooling and exams have been affected.
She has “tried to block the memory of the incident out” and is hoping to meet with a counsellor soon.