The promising teenage sportsman appeared in the ACT Supreme Court on Tuesday, and was sentenced by Justice David Mossop to a fully suspended jail term of 11 months.

The rapist cannot be identified and has been given the pseudonym John Smith by the court because he was under 18 at the time of the April 2018 offending.

Justice Mossop said the victim, who was the same age, picked Smith up from an 18th birthday party on the night in question.

They went to an oval, where a drunken Smith chased kangaroos in the dark before what started as consensual sexual activity in the back seat of the victim's car.

When Smith asked the victim if he could give her oral sex, she said no. He went to do it anyway and licked her thigh.

Smith subsequently penetrated the victim multiple times, despite her repeatedly telling him not to.

The victim eventually gave up protesting, turned her head and cried until Smith finally stopped and asked her: "What, were you being serious?"

After a four-day judge-alone trial earlier this year, Justice Mossop found Smith guilty of two counts of sexual intercourse without consent and one count of committing an act of indecency without consent.

Smith continues to maintain his innocence and has lodged an appeal against his convictions, arguing the judge's verdicts were "unreasonable having regard to the evidence".

In sentencing on Tuesday, Justice Mossop said Smith's continued denials meant he had not expressed any remorse or insight into his offending.

However, the judge said it worked in Smith's favour that his attitude had changed drastically at the sight of the victim's tears and that he had "desisted" from continuing after realising "he had gone too far".

It was important, Justice Mossop said, to consider the "significant level of harm" Smith had caused the victim and her family, who gave statements detailing her subsequent suicide attempts and what the victim called "an indescribable sickness".

The court heard the victim's personality had changed dramatically, and she could not even get back into her car after what occurred inside the vehicle.

But the judge said he also had to take into account that he considered Smith to pose "a low risk of future offending".

This was partly because Smith's crimes had made him the target of significant "social opprobrium", which would prove a powerful deterrent for any repeat behaviour.

The court previously heard the rapist had "received a lot of hate" and threats from people who knew his true identity, while he had also been assaulted in Civic.

Justice Mossop sentenced Smith to a wholly suspended term of 11 months in jail on the two rape charges. He also ordered the rapist to complete 100 hours of community service as part of associated 18-month good behaviour orders.

On the act of indecency charge, the judge imposed a six-month good behaviour order.

Justice Mossop also found it would be "inappropriate" to have Smith register as a child sex offender, given the victim was the same age as Smith and there was no evidence of ongoing sexual attraction to children.

Smith showed no emotion as he was sentenced, and once Justice Mossop had left the courtroom he lounged back in a chair with his arms folded.

The rapist's father, who previously told the court his son was "very respectful" of women, let out a huge sigh of relief when Justice Mossop made clear that he would not be imposing a custodial sentence.