German tourist Maxim Wecker has been remanded in custody after appearing in court on a grievous bodily harm charge over a one-punch attack on the Gold Coast.

A 23-year-old Oxenford man is in hospital in a critical condition after he hit his head on the footpath when he was punched while trying to stop a fight between two groups of men on Orchid Avenue in Surfers Paradise just after 3:00am.

Police said the man was punched from behind and fell to the ground.

Detective Acting Senior Sergeant Mark Mooney said police had been trying to work out why the fight started.

"We are still investigating that at this stage, investigators are still taking witness statements and viewing CCTV footage in order to determine that," he said.

The street was cordoned off by police. ( ABC News )

Senior Sergeant Mooney said the first police officers on the scene saved the victim's life.

"Upon arrival the victim was actually in a critical condition already and the first response police officers were required to conduct CPR in order to resuscitate him."

The ABC understands the man did not know those involved in the scuffle.

Wecker, 29, did not apply for bail when he appeared in the Southport Magistrates Court Friday afternoon charged with grievous bodily harm.

Senior Sergeant Mooney said German authorities had been contacted.

A 27-year-old man also linked to the incident was charged with public nuisance.

The other men involved in the fight fled the scene.

Wecker is due to appear in court again on November 15.