Ainsley went on to win junior and senior titles at the national wrestling championships in the 86kg category.
The move from Katikati in the Bay of Plenty to Dunedin was eased by a Māori and Pacific Peoples' Scholarship from the university, worth $10,000.
But in May 2019, several months after breaking up with his girlfriend, Ainsley contacted her, requesting her assistance with a medical matter.
She initially refused and the defendant's messages became abusive.
Eventually the woman agreed to see him in a bid to defuse the animosity.
But as soon as she arrived at Ainsley's home, he demanded an apology and continued to berate her.
He poured a bottle of water over her head, forced her against a wall and smeared the liquid over her face and hair as she cried for him to stop.
Ainsley demanded she remove her wet top and ripped it off when she refused.
There was a brief respite when Ainsley became apologetic, the court heard, but his temper soon flared again.
The victim asked to borrow clothes so she could leave the address.
Instead, Ainsley ripped her bra off, causing a material burn across her chest.
He pushed the topless woman into the hallway of his flat and told her she could walk through the campus half naked.
She sat on his bed crying and the defendant put his hand over her mouth to stifle the noise.
When she continued, he hit her in the stomach.
Unless she calmed down, Ainsley said, he would rip her tights off too.
He pulled them up, lifting the victim off the ground and dropping her to the floor.
She covered herself in her ripped clothing and left.
"Not one but several assaults over an extended period," Judge Michael Crosbie said.
Ainsley shook his head in the dock, which prompted the judge to outline the various points at which he could have stopped the onslaught.
"[It was] degrading, humiliating, traumatic and had a really lasting effect on her," Judge Crosbie said.
Defence counsel Jim Takas said Ainsley had legitimate prospects of pursuing his professional sporting dreams.
He had received a contract offer from a Melbourne rugby club, which was on hold while he finished his degree.
"The defendant accepts the offending is serious but the effect of a conviction is so serious, it's dire really," Takas said.
"Professional athletes can survive run-ins with the law once they are established but in the early days it can be a death sentence."
In a letter to the court, Ainsley wrote that he was "truly sorry" for what he did.
He described the victim as a "kind, sweet girl", prompting an interjection from Judge Crosbie.
"She's not a girl, Mr Ainsley, she's a woman," he said.
The victim said her self-esteem had taken a huge blow since the attack and she consistently felt unsafe.
While the judge accepted there would be some impact on Ainsley's life, the offending was too serious for a discharge without conviction.
"I regard this as an aberration in your life," he told the defendant.
"You're one of many young men who's fallen foul of the law but that doesn't need to define you."
Ainsley was sentenced to nine months' supervision and a protection order was made in favour of the victim.
rob.kidd@odt.co.nz
