Two men on trial over the hit-and-run of an Indigenous teenager in South Hedland allegedly went in search of a group of teenagers who had been wandering the streets of the town.

The local Supreme Court on Tuesday heard that in May 2016 just after midnight, a 14-year-old boy pedalled "furiously and in a panic" as a car allegedly followed him through a dark and vacant block in the regional Western Australian town.

The court heard the teenager tried to lose the car by taking off through a storm water drain in the area known to locals as The Flats.

The passenger in the car is alleged to have yelled out, "I'm going to kill you, you black c**t", the court was told.

Two South Hedland men are on trial, accused of striking the bike and throwing the teenager to the ground.

The police prosecutor told the court the boy suffered a badly broken leg and was left to "crawl, hop and drag himself" to medical help.

Robert Peter Butson and Zachary Kane Armstrong have been charged with causing grievous bodily harm, failing to render assistance, destroying evidence and attempting to pervert the course of justice.

They have pleaded not guilty to all charges.

'Big dog, little car and two men'

In his opening address, prosecutor Anthony Eyres told the South Hedland Supreme Court that the sequence of events had started earlier that evening.

The court heard the teenager had to be flown to Perth for medical treatment. ( ABC North West WA: Ewan Gilbert )

A group of teenagers, including the alleged victim, had been wandering the streets and ended up outside Mr Armstrong's house.

"What the kids were up to you can draw your own inference," Mr Eyres said.

When Mr Armstrong spotted a young girl trying to open his front door, he allegedly chased the group away on foot.

My Eyres told the court Mr Armstrong and Mr Butson then drove to Mr Butson's nearby home, where they picked up a large mastiff dog and swapped into Mr Butson's mother's car.

"They then drove off … in search of the children," Mr Eyres told the court.

"Big dog, little car and two men."

It is alleged that when they spotted the 14-year-old on the bike, they gave chase across The Flats.

"[It was] unlit, dark and undulating [terrain]," Mr Eyres said. "And [the teenager] pedalled away furiously in a panic."

Mr Butson's defence team said their client had admitted he was driving the car that night and that he was involved in destroying it later by fire.

But they said they would be arguing the evidence was not strong enough to convict Mr Butson of actually causing the injury or destroying evidence.

Mr Armstrong's lawyer elected not to give an opening statement.

'I thought I was going to die'

The now 16-year-old victim gave evidence via video link.

Under cross-examination he conceded his memory of the events that night was imperfect, but he told the court he clearly remembered being chased and hit by the car.

"I thought I was going to die," he said.

"I thought they were going to come back and finish me off."

He denied any role in events earlier that evening, and said he was unaware of what others in the group of teenagers had been doing.

The trial is expected to last until early next week.