Australian Sevens captain Lewis Holland has told a Sydney court he heard a "bone-crushing sound" and former teammate James Stannard fall to the ground before players chased down the alleged attacker in Sydney's eastern suburbs.
Sam Oliver is accused of punching Australian rugby sevens veteran James Stannard outside a kebab shop in Coogee in the early hours of March 30.
Stannard missed the Commonwealth Games due to injuries sustained in the attack and later retired.
"I heard a bone-crushing sound ... I say that because I play rugby and I know the sound," Australian captain Lewis Holland told Downing Centre Local Court on Monday.
Holland said he wasn't aware of any conversation between Stannard and anyone else before the incident.
He told the court he then chased down a man who ran from the scene and found him between two cars.
"I arrived and just made a tackle," Holland said.
The court was told then-coach Andrew Friend subsequently helped Holland detain the man.
Friend - who left the team after the Commonwealth Games in April - was being farewelled earlier that night at a Rugby Australia function in Coogee before he and some players moved to the Coogee Bay Hotel.
Oliver has pleaded not guilty to both assault occasioning bodily harm and causing grievous bodily harm.
His lawyer argues Stannard called his client a "Pommy c***" in an earlier altercation.
Holland and teammate Ben O'Donnell, who also gave evidence on Monday, say they didn't hear an argument or see any punch thrown.
Stannard also gave evidence on Monday, denying an accusation that he had provoked Oliver that night.
Oliver's lawyer told the court on Monday that the altercation only occurred after Stannard's alleged provocation.
Asked his memories of that night, Stannard told the court the last recollection he had was of the band at the Coogee Bay Hotel and did not remember speaking to Oliver at any stage.
The 35-year-old told the court his next memory was waking up in hospital with 'an extremely sore head' and bleeding out of his ears.
Stannard returned a blood alcohol reading of 0.23 when he was admitted to hospital, the court head on Monday, a level equivalent to high-range drink driving.
"I had an extremely sore head and I had blood coming out of my ear," Stannard said.
"I was quite anxious, and I didn't know what was going on."
Friend's son Josh was present on the night and gave evidence on Monday
“I saw James Stannard’s eyes go in the back of the head, there was a loud whack … he went stiff as a board,” he said.
Bystander Mark Tobin also provided evidence, saying he saw an exchange between the two men in the early hours of that Friday morning.
The hearing continues on Tuesday.