A man was killed after being knocked unconscious by a single punch thrown by a friend, while louts placed cigarette butts in his nose as he lay dying.
Richard Thompson, 42, was punched by Jamie Garwood, 34, at his home in Newport, Wales, on August 30 last year.
Garwood was sentenced to six years in prison for inflicting the fatal blow.
It was an assault that was to have catastrophic consequences.
All those present at the house had been drinking and taking drugs, including Mr Thompson, and the defendant had been smoking cannabis.
A sentencing hearing at Cardiff Crown Court on Thursday heard Mr Thompson and his partner Jenny Chard's home in Tewkesbury Walk had been "cuckooed", taken over by those involved in drug dealing to be used for their practices.
Garwood was not involved in that, but knew Mr Thompson well and knew he was addicted to class-A drugs and was vulnerable, WalesOnline reports.
Prosecutor John Hipkin KC described how the tragic incident unfolded one of the men in the house, Carlos Ross, began "bullying" Mr Thompson by throwing small items at him.
The victim told him to stop, and eventually reacted by throwing a small tin or pencil case, which struck Garwood on the head, causing a small lump.
Mr Hipkin said: "The defendant then, in short, threw a left-handed punch which struck Mr Thompson on the chin. Mr Thompson fell to the ground and his head struck an uncarpeted surface. The defendant's partner Vicky Moody described the sound as 'sickening'.
"Mr Thompson was unconscious for a number of minutes, he regained consciousness at one stage but his condition deteriorated and he couldn't be raised. Jenny Chard telephoned an ambulance two hours after the blow I described. During that time Ms Chard saw individuals put cigarette butts in Mr Thompson's nose as he lay unconscious on the sofa."
The barrister said Garwood and Ms Moody had gone to assist Mr Thompson after he had been injured and the defendant had walked with him outside before he fell back into unconsciousness. Both left before the arrival of the ambulance.
Paramedics arrived at Mr Thompson's home in Tewkesbury Walk at 12.26am on October 31 and found the victim lying on his back on the sofa, his left eye open and his right one closed. He made no reaction to their presence and showed signs of having suffered a serious head injury. There were also signs he was a heavy user of alcohol and intravenous drugs, and there were abrasions to his right eye.
Mr Thompson was taken to the University Hospital of Wales in Cardiff but did not regain consciousness and died on September 6, 2022.
A post-mortem was carried out which revealed he had suffered skull fractures to both sides of his head and subdural and subarachnoid hemorrhages, believed to have been caused by a blunt force moving head injury.
On September 9, Garwood and Ms Moody went to stay with a friend and told him Mr Thompson had been "paralytic drunk", and Garwood said he "needed to think about what to do".
He was arrested later the same day by police and gave a no-comment interview. The defendant later pleaded guilty to manslaughter on December 15 last year.
Mr Hipkin told the court Garwood had a long antecedence record of 34 previous convictions, for offences including common assault, robbery, affray, battery section 20 wounding, domestic assault, assaulting a police officer violent disorder, attacking a cellmate while in prison, and burglary.
He was subject to post-sentence supervision at the time of Mr Thompson's death.
In mitigation, Davie Elias KC said there was a clear lack of premeditation in Mr Thompson's death, and his client's actions amounted to a "reaction". He said the defendant "bitterly regretted" his actions and said it would "live with him for the rest of his life".
Sentencing, the Recorder of Cardiff Judge Tracey Lloyd-Clarke said: "Your reaction to being accidentally struck by an object thrown by Mr Thompson was to use violence without any thought of the consequences, which you have often done in the past. This time the consequence was Mr Thompson tragically losing his life."
Garwood was sentenced to six years imprisonment, with an extended licence period of four years.
He will serve at least two-thirds of the custodial period before he will be considered for release.
