Sydney man Ricky Kevin Lefoe, 32, stood trial this week in the Brisbane Supreme Court accused of the manslaughter of Brazilian national Ivan Patricio Susin, then aged 29, at Surfers Paradise.

Crown prosecutors and Lefoe's defence agree that he punched Mr Susin just after 1am on October 1, 2019 outside an Orchid Street kebab shop, causing him to fall and suffer head injuries that claimed his life 10 days later.

The fatal blow resulted from a brawl that started when Lefoe's intoxicated friend Shaun Simpson grabbed at a container of chips that two of Mr Susin's friends were eating from while sitting outside on a bench.

Lefoe's barrister Patrick McCafferty told the jury his client took action because Mr Susin had attempted to throw a powerful punch at his friend from behind.

"Lefoe's punch, which unfortunately proved fatal, was lawful because it was thrown by him in order to save Shaun Simpson from serious harm threatened to be inflicted upon him by Ivan Susin," Mr McCafferty said in his closing statement on Tuesday.

"Or it was in good faith in self defence of his friend."

Mr McCafferty told the jury they had a "critical" role to assess Lefoe's state of mind when he saw Susin attempt to throw a punch at Mr Simpson while his back was turned.

"He had to make a split second decision about the threat posed by Susin when he threw that punch - he didn't have the ability to pause or slow down," Mr McCafferty said.

The defence barrister's closing came after a day-and-a-half of testimony from prosecution witnesses.

The defence's sole witness was Lefoe himself, who chose to take the stand in his own defence earlier on Tuesday.

Mr Lefoe told the court he was aged 29 at the time and was on a family trip to the Gold Coast and had met up with Mr Simpson after not seeing him for a long time.

Mr Lefoe said he had gone to buy cigarettes from a nearby convenience store just after Mr Simpson started "clowning around" and grabbed a chip from Mr Susin's friends.

"I walked out of the shop and there were two people on the ground fighting and I realised one was my mate," Mr Lefoe said.

"My first reaction was to break it up ... then from out of nowhere someone has come from behind me and thrown a big haymaker to the back of my friend's head."

Under cross-examination by crown prosecutor Elizabeth Kelso, Lefoe conceded he grabbed Mr Susin's shoulder before punching him.

"Your motivation was to keep other people out of the fight, you just wanted it to be between Shaun and (Susin's friend) Johnny?" Ms Kelson said.

Lefoe replied: "I didn't want there to be a fight at all. I was on holiday with my mum."

In her closing statement, Ms Kelso said Lefoe had never bought cigarettes and instead watched Mr Simpson pin a smaller man to the ground and punch him repeatedly.

"(Lefoe's) true motivation was not to protect his friend from death or grievous bodily harm, it was to let his friend - who from start to finish was the aggressor - to continue his fight with (Johnny) without interference."

The jury were due to retire to consider their verdict on Wednesday following directions from Chief Justice Helen Bowskill.

Australian Associated Press