Murder accused said he'd 'stab' love rival

A man told a friend he was going to stab a love rival days before he allegedly ambushed the victim in an apartment complex hallway and murdered him, a Perth court has heard.

Daniel James Carrington is on trial in the West Australian Supreme Court accused of repeatedly stabbing father-of-four Benjamin Egan in Northbridge in April 2017.

Christine Ward testified on Wednesday that the men had an ongoing quarrel but she was shocked when Carrington told her: "I will stab him."

"At the worst, I would expect a few punches but definitely ... you do not do that," she said.

Under cross-examination, Ms Ward rejected the suggestion she was mistaken about the conversation.

"I would disagree with that (assertion)," she said.

Ms Ward also denied ever having an intimate relationship with Carrington or holding a grudge against him.

She admitted she had been a drug user in the past but had been rehabilitated.

The court previously heard Mr Egan and Carrington had become friends years earlier when they were neighbours and Mr Egan would stay with Carrington whenever his partner kicked him out.

But their friendship soured after Carrington had a short relationship with the woman and Carrington learnt Mr Egan had allegedly broken into his storage unit.

CCTV footage played in court showed part of the fatal attack, followed by Carrington briskly walking out of the building then running away.

Defence counsel Jonathan Davies said his client acted in self-defence after Mr Egan had created a "climate of fear" for Carrington, who believed his life was in danger.

The trial continues.