A man accused of a frenzied and fatal stabbing in the middle of Westfield Parramatta shopping centre will defend the murder charge against him, his lawyer said outside a Sydney court on Tuesday.

Kazem Mohamadi Payam, 35, was charged with murder after he allegedly stabbed a man, 40, to death in front of horrified workers, shoppers and children on Monday morning.

He did not apply for bail but was formally refused before Parramatta Local Court.

Police will allege the Iranian-born man carried out the bloodied attack outside the cosmetic section of Myer following a heated argument over a woman.

Just 24-hours after the killing, Mr Payam sat in the holding docks of the courtroom scratching his head and playing with his beard.

He spoke briefly to a Farsi interpreter and nodded to a woman sitting in the public gallery.

His lawyer said she expected her client would apply for bail when he next appeared before the same court on July 24.

Detectives say the accused, who was living in Parramatta at the time of the attack, had targeted his victim and plunged a knife repeatedly in this chest and neck several times.

Blood curdling screams of workers echoed through the halls of the mall with some women heard yelling "He's killing him!".

As hundreds of children watched the Wild Animal Encounters Reptile Show a few floors below, up to 30 police swooped on the centre and rushed to close off every entrance to Myer.

As the 35-year-old deceased lay motionless outside a shoe store, the alleged killer ripped off his shirt and lit a cigarette as he waited for police to arrest him.

One man who saw the attack from the level above said he watched horrified as the killer drove the weapon into the victim.

"He kept plunging the knife in his chest, in and out, and paced up and down the shopping centre screaming at police," said the man, who did not wish to be named. "He taunted the police, [saying] 'what are you scared of?'

"Everyone was very scared and begging for someone to stop the attack...there was blood everywhere."

The metal shutter doors of Myer were shut at every entrance and distraught workers were locked inside for several hours as police collected evidence from the crime scene.

Acting Superintendent Jennifer Scholz said the stabbing was not gang-related and that it was an isolated incident between the two men.

More to come