A man who viciously assaulted a gay lover, set fire to his apartment and left him for dead is due to be sentenced for murder.

Lane Tynan Mitchell, 25, and Peter Anthony Jarman, 49, had sex and took methamphetamine in the older man's North Perth apartment in June last year before an argument erupted.

Peter Anthony Jarman died during a blaze at his North Perth apartment. Credit:WA Police

Mitchell, who provided the drugs, became enraged when Mr Jarman refused to give him cash for a taxi fare.

He admitted punching, kicking and bludgeoning Mr Jarman with a wine bottle, although a forensic pathologist said the victim may also have been hit with a statue and a frying pan.