A New Zealand man has pleaded guilty to the one-punch death of Brisbane teenager Cole Miller.
Mr Miller and a friend were walking through the nightclub district of Fortitude Valley on January 3 when they were attacked by four men.
One of the men allegedly told his friend "do you want to see something funny" before randomly challenging Mr Miller to a fight and throwing the first punches.
Armstrong Renata then came from behind and punched the 18-year-old in the head, causing massive brain trauma. He died in hospital the next day.
Renata, 22, pleaded guilty in the Brisbane Magistrates Court on Wednesday to unlawful striking causing death. He will be sentenced in the Supreme Court later this year.
A second man is still facing charges over Mr Miller's death.
Mr Miller was an elite water polo player and had been on track to follow in the footsteps of his brother Billy, who was part of the Australian men's team at the London 2012 Olympics.
"It was about to be Cole's time to shine," Billy Miller told a 2000-strong memorial rally in Brisbane a week after the teen's death.
"Cole was about to live out his dreams."
Renata was charged under tough new laws introduced in Queensland in 2014 designed to combat alcohol-fuelled violence.
He faces a maximum penalty of life behind bars and will have to serve 80 per cent or 15 years of any jail sentence handed to him.