A Melbourne chef accused of stabbing a man to death in a Chinatown car park in broad daylight told an eyewitness he had been under attack, a Melbourne court has heard.

Fai Sing Yiu, 59, of Forest Hill is accused of murdering Alan Wong, 64, in the Golden Square car park at lunchtime on October 29 last year.

The prosecution says after Mr Wong came to Yiu's restaurant, Yiu walked him around the corner to the car park where Mr Wong was killed in a "frenzied attack".

At Yiu's committal hearing on Wednesday, witness Lynda Davies said she saw him stabbing the victim, who was holding his arm up trying to protect himself.

"They were pushing each other. They were yelling at each other," Ms Davies told the Melbourne Magistrates Court.

"The small man then produced a knife and began stabbing. He was jabbing at the other gentleman.

"The other gentleman was jumping backwards to avoid the knife."

She said the victim was "holding his arm up".

"He was trying to protect himself," she said.

Ms Davies said Yiu didn't realise she had seen what had happened and when he left the car park, covered in blood, he told her he had been under attack.

"He said: `He tried to commit suicide. He tried to rob me', he said a few things," Ms Davies told the court.

Yiu had been overheard arguing on his phone at the Post Deng Cafe, where he worked, before the incident, the court heard.

Yiu's defence barrister told the court earlier this year Yiu would argue self-defence.

He said the defence case was that Mr Wong turned up at Yiu's restaurant in a "fit".

Yiu was committed to stand trial for the murder of Mr Wong and will face the Victorian Supreme Court on Thursday for a directions hearing.

© AAP 2015