A thug beat a Good Samaritan to death in a street in Wembley street because he tried to stop a vulnerable woman from being abused on Valentine’s Day, a court was told today.

Omer Jama Abdi, 35, died after being viciously assaulted in St John’s Road, after intervening in an argument between his friend Filsan Abubakar and Osman Mahdi, 28, on February14, 2012, the Old Bailey was told.

Mahdi allegedly launched a ‘wholly unjustified and vicious’ assault on the victim, raining down punches and kicks as he lay helpless on the floor.

Prosecutor Bobbie Cheema QC said: “There was no lawful reason for the defendant to assault Mr Abdi, who had done him no wrong at all but simply intervened to try and get him to leave the woman alone.’

Ms Abubakar and Mr Abdi were drinking together in her flat when Mahdi arrived and began arguing with her in the street outside, the court heard.

The defendant allegedly spat at Ms Abubakar and called her a ‘black b*tch’.

“Mr Abdi came out and said to this defendant ‘just leave her alone, she’s a lady and you’re a man,” Ms Cheema told the jury.

After the attack Mahdi left his victim lying on the ground before coming back minutes later and kicking him repeatedly where he lay, it is claimed.

Mr Abdi, who suffered from a serious heart condition, was found unconscious at around 2.20am and was pronounced dead in hospital.

Mahdi was arrested a year later and claims he attacked the victim in self defence, the court heard.

A postmortem report found the cause of death was coronary heart disease with a causational link to the assault.

Mahdi from Kensington, denies murder.

The trial continues.