His name was in the media and family members were seeing it there along with photos of the crime scene while he was in hospital with fatal head injuries - the Crown described them as "catastrophic".
Levi's father Glenn Haami said he was pleased that the guilty plea "means we don't have to get dragged into the court process more than we have to".
Williams described Levi as "a beautiful, kind soul, always laughing, always happy". Glenn Haami said he had "a beautiful energy".
Half the court's public seating was filled with family and supporters wearing black t-shirts with the message, justiceforlevi, and an image of the teenager with angel wings.
The group sat quietly through almost all the hearing, but shouted two comments as he was led back to the cells to resume his time in custody. One person called him "scum".
Another called out, "Shame on you, Moana", at Cole for her announcement that the youth would appeal to continue his name suppression order.
The youth was originally charged with murder but has pleaded guilty to the manslaughter charge after the Crown agreed to reduce it a few weeks ago.
Defence counsel Chris Lange asked for the youth's case to be called today, so that the guilty plea could be entered, two weeks before the youth was due to stand trial.
Crown prosecutor Kerry White then told the court about the events at a gathering of young people who had between 30 and 50 cars at the Countdown car park about 2am on December 4.
She said the youth and Levi had met each other at least once before, at a social occasion.
Levi was at the car park as the driver of a car with four associates, when he went to some bins near the Madras St corner to urinate.
A vehicle drove past with the other youth sitting on the window sill with his torso outside the car. He could see Levi as he passed, and Levi called out: "Why are you looking at my d--k?"
The vehicle then made a u-turn into the car park, and the attacker got out of the car, visibly agitated. He walked up to Levi, shouting abuse, and punched him in the side of the mouth. He fell backwards, striking his head.
Witnesses say the attacker also kicked Levi in the leg, but they disagree on whether that happened before or after the punch.
The attacker left but the car returned a few minutes later with him still sitting outside on the window sill. By then friends were performing first aid. The attacker called out: "Is he breathing? Is he up yet?"
White said Levi received "catastrophic brain injuries" and his life support was turned off in hospital at 4.40pm the next day, after a brain scan.
Justice Nation asked for a pre-sentence report for the sentencing. Cole said the defence would also seek a report on his cultural background, and a neuro-psychiatric report. She had originally asked for suppression to be continued until those reports could be prepared and considered.
