Man pleads guilty to NSW Westfield murder

An Iranian immigrant has pleaded guilty to stabbing his ex-lover's boyfriend to death at a busy western Sydney shopping centre.

Kazem Mohamadi Payam attacked 40-year-old Nabil Naser in front of horrified shoppers at Parramatta's Westfield shopping centre last July.

He pleaded guilty to the crime at the Supreme Court on Friday via video link from prison and will be sentenced in July.

Payam entered the plea in English despite the presence of a Farsi interpreter.

Police say Payam bought a knife from a Westfield shop while on his way to meet Nasser to discuss a domestic matter on July 7, 2014.

Some 110 people, including 10 police officers, had given statements, a court heard last year.

The government has confirmed Payam was an "illegal maritime arrival" who was granted a protection visa in February 2010.