Lloyd Saunders (33), of Seven Oaks, Swords Road, Dublin 9, had pleaded not guilty at Dublin Circuit Criminal Court to assault causing harm, false imprisonment and making a threat to kill or cause serious harm at Rathvilly Park, Finglas, on December 17, 2016.
The jury convicted him of assault causing Kelly Evans harm but failed to agree on the other two charges.
Ms Evans told the jury during the trial last March that Saunders hit her in the face with his open hand three or four times.
She said she stood up to leave and he said that she was not going anywhere after slamming the bedroom door.
Ms Evans said he continued to slap her and began strangling her while she tried to fight and scream.
She said at one stage he went to get a tissue to clean her face.
She said that when he returned, he propped her up and asked if she was "ready for round two?" before subjecting her to a further assault.
She said the assault went on for "at least an hour and a half" and came to an end when he let her leave the house.
Garrett McCormack BL, prosecuting, reminded Judge Pauline Codd of Ms Evan's father's evidence during the trial of being contacted by his daughter after the assault and the significant injuries she had on her face when he met her.
He said that Saunders had denied the assault during a subsequent interview with gardaí and claimed Ms Evans had arrived at his home with those injuries, a claim which Ms Evans had "vehemently denied during the trial", Mr McCormack said.
A victim impact statement said Ms Evans was unable to go to family gatherings that Christmas due to the bruising on her face and neck.
She said she suffered extreme anxiety, depression and post-traumatic stress disorder.
"I could have recovered a lot quicker if he had pleaded guilty but instead he dragged me through the courts," Ms Evans said.
She added that giving her testimony and having to listen to her 999 call during the trial had "a major impact on my mental health".
"I have waited five years for this to be resolved, only now can I restart my life," she said.
The court heard Saunders had 10 previous convictions for public order offences, criminal damage and road traffic offences.
Ciaran O'Loughlin SC, defending, handed in a number of testimonials on behalf of his client, including from his employer, mother and current partner.
His current partner said she never witnessed this kind of behaviour from Saunders.
He was described as an honourable person and a care-giver to his grandparents.
Sentencing Saunders yesterday, Judge Codd said it was a very serious, prolonged assault on a vulnerable woman within the context of an intimate relationship which she said Saunders had been fully engaged in.
She said Saunders asking Ms Evans if she was ready for round two was "a most intimidating utterance" in the context of a prolonged assault and noted that Ms Evans was left with extensive bruising to her face, head, eyes and neck where she had been throttled.
"A father finding his daughter in that state should not be visited upon the father of any young woman. It was a horrendous scene.
"She was highly distraught and visibly black and blue," the judge said, referring to Ms Evans' father's evidence during the trial.
She acknowledged from the various testimonials that the "conduct was out of character".
She imposed a three-and-a-half-year sentence, with the final six months suspended on strict conditions.