"Every time we met she started undressing."
But the judge said today she completely rejected his version of events.
The pair met on social networking site "Tagged" and the teen told Ali she was not looking for a relationship because she was still in love with her former partner.
He told her he could make the man come back to her by undertaking some "spiritual activities" and in March last year they arranged to meet.
The woman got into Ali's car and he said he would have to molest her for the plan to work.
She submitted to the abuse and met him the following day in Mt Wellington.
He told her that in order to "speed things up" they should have sex, which would mean the teenager and her ex-boyfriend would be back together within a week.
"It would have been very clear to you she was suffering from an intellectual disability," Judge Johns said.
In a victim-impact statement to the court, the teen said she could barely remember what life was like before the abuse.
"I feel like my whole personality has changed from a friendly, fairly-outgoing girl to a person with no confidence," the woman wrote.
She said she had nightmares regularly and was scared to sleep as a result.
"Prior to your offending it seems she was living a fulfilling life but your actions have taken her ability to do that away from her," Judge Johns said.
Ali was given credit for his lack of previous convictions, his rehabilitation efforts and his guilty plea.
It was recommended he enter a specialist sexual-offender programme while serving his jail term.