"Often what brings people here is totally unimpressive and in large part it's what happens from here that's important," Judge Grant Fraser said.
"I'm extraordinarily impressed with the work you've been doing."
The court heard how the assault charge came about after "sustained shoving", but the judge accepted it was at the lower end of the scale in terms of its seriousness.
On Thursday, the defendant told the court he was now a father, after his partner gave birth at the end of last year.
At a previous court appearance, he highlighted that as a motivating factor for his rehabilitation and said his attendance at Alcoholics Anonymous had been extremely positive.
"The support from people in AA has been really helpful," Lotu-Iiga said. "Being able to sit down with like-minded people who have gone through the same thing; it's been able to keep me clean. It's been the longest I've been clean since 11 years old."
A letter to the court from his partner spoke about his "huge progress", and Judge Fraser said that should be reflected in his sentence.
He ordered Lotu-Iiga to complete a year's intensive supervision, which would allow him to continue undertaking counselling.
The judge also imposed judicial monitoring so he would receive reports every three months on Lotu-Iiga's progress.
"You won't see me again unless things deteriorate," Judge Fraser said. "They will if you start drinking again, and you know that."
Sam Lotu-Iiga refused to comment on this week's sentencing.