Dominic Calabro, 40, stood trial in the West Australian Supreme Court over the death of Andrew Minh Tran, 29, at Calabro's Balga home in July last year while they were both affected by methylamphetamine.

When Mr Tran arrived unexpectedly at Calabro's house, he punched him at the doorway and walked inside.

Calabro then tied up, beat and repeatedly stabbed Mr Tran before cutting his throat.

Prosecutor David Jubb said the injuries were inflicted in a "painful, prolonged and brutal" way.

Calabro testified during the trial that "in essence" he was defending himself against Mr Tran, who had been violent and menacing during the four prior days, and said he had to defend himself from future threats.

"I didn't believe I had a choice in the matter," he said.

Defence counsel Simon Freitag told the jury Mr Tran treated Calabro "as his butler, servant, sidekick".

"He clearly took a lot of abuse, a lot of violence and threats before he physically responded," Mr Freitag said in his closing address on Friday.

Mr Tran was also violent and menacing to others, including his girlfriend who he threatened to throw off a balcony, Mr Freitag said.

But Mr Jubb said it was a clear case of murder rather than self-defence, adding there was nothing necessary or reasonable about Calabro's actions.

He suggested Calabro could have instead gone to police.

Calabro denied he was acting out of revenge and said after the first stab, he was a "passenger to it".

"I'm proud that I survived an ordeal," he said.

"I'm glad that I'm alive and if that meant he had to die then so be it."

After the killing, Calabro visited his ex-partner and two children.

He tried to flag down a police car and walked into a police station before calling officers to tell them there was a body at his house and he would wait for them at a fast food outlet.

The jury returned its verdict on Monday afternoon.

Calabro will face a sentencing hearing on January 31.

Australian Associated Press