A German backpacker was struck over the head with a hammer and run over by a 4WD after her friend had been sexually assaulted on a remote beach in South Australian, a court has heard.
Earlier that evening, the woman's friend, a Brazilian backpacker, was allegedly tied up and had her bikini cut off her with a knife by a man who is now on trial in the Supreme Court.
The 60-year-old is charged with attempted murder, kidnapping, indecent assault and other offences over the alleged attack on February 9, 2016.
Opening the trial on Thursday, prosecutor James Pearce said the backpackers met the man through classifieds website Gumtree when they sought a lift from Adelaide to Melbourne.
He picked them up and drove them to the isolated beach at Salt Creek in the Coorong National Park, the court heard.
The German woman was taking a nap in the car when the man offered to take the other backpacker for a walk to spot kangaroos.
But he threw the Brazilian woman to the sand and pulled out a knife, the court heard.
He tied her arms behind her back with rope, cut off her bikini and kissed her body all over, the jury heard.
"With the flourish of the knife she was naked, lying on the sand. She was helpless," Mr Pearce said.
"She thought she was going to die. She had to think of a way out."
In the hope it might save her life, the woman told her attacker they would be more comfortable back at the tent.
But as he led her back to camp she screamed, waking her German friend in the car.
When she got out of the vehicle and saw them, her bound and naked friend told her to flee.
The German woman ran back to the car to get to her phone but the man followed, hitting her several times in the head with a hammer.
With four gashes to her head and blood streaming into her eyes, she ran across the dunes, Mr Pearce said.
But the accused man started the 4WD and chased her down, ramming her with the bull bar several times.
"He mowed her down," Mr Pearce said.
"On one occasion, the car literally ran over her. Fortunately, the wheels went either side of her." As she couldn't outrun him she jumped on the car's bonnet and climbed on to the roof.
He tried to throw her off, tearing up and down the shrubby dunes, but eventually the car became bogged.
Meanwhile, the Brazilian woman had untied herself and managed to flag down a car of four young fishermen, who called police.
The German woman also fled, stumbling along the beach towards the stunned fishermen.
"Her hair was so drenched with blood that you could've wrung it out like a wet towel," Mr Pearce told the jury of eight men and four women. Police found the accused man stuck in the dunes and arrested him inside his 4WD. In a brief address to the court, defence counsel Bill Boucaut urged the jury to keep an open mind.
"Sometimes things are not always what they appear to be," Mr Boucaut said. "The issue will be about whether these things happened the way they say things happened."
The trial continues, with the jury to visit Salt Creek on Friday to view the key locations.