A drunken reveller was jailed for killing his best friend in a one-punch attack, after an argument before pleading with him: "Get up, get up."
Jay Webster, 28, had been drinking with his friend Benjamin Lloyd, 27, before the pair headed into town for a night out.
But Webster was turned away from a pub for being too drunk - and the pair became embroiled in a "silly argument" outside a library.
A court heard witnesses watched in horror as Webster punched Mr Lloyd to the head before he was sent crashing to the ground.
Curtis Jeremiah said: "I can recall Mr Lloyd hitting the ground hard and the noise was horrible.
"It was almost like the sound of a snap as his head hit the ground."
Cardiff Crown Court heard Webster appeared "absolutely devastated" as he stood over his best friend, frantically saying: "Get up Ben. Get up."
Prosecutor James Wilson said CCTV footage captured the moment the violence was sparked on April 1 this year.
He said: "The defendant pushes Mr Lloyd up against a window. Mr Lloyd takes two swings and misses.
"The defendant punches Mr Lloyd to the left side of his face with his right fist and he falls to the ground."
The court heard Webster told onlookers he "did not mean to do it" after they had a "silly argument" in Caerphilly, South Wales.
He stayed with his friend as witnesses called for an ambulance before Mr Lloyd regained consciousness after three minutes.
Webster left the scene before he made his way to a pub - and later visited the victim's mother.
Mr Wilson said: "The defendant attended the home of Mr Lloyd's mother Kay Main. She described Ben as having been a brilliant friend to the defendant."
The court heard Webster told Ms Main: "I'm sorry, me and Ben had an argument."
Mr Willson said the worried mother called her daughters to tell them what had happened, before putting an appeal on Facebook.
The court heard victim Mr Lloyd refused to wait for an ambulance at the scene but instead tried to get into a taxi.
Police arrived to find him with dried blood in his mouth before Mr Lloyd told officers he did not need medical assistance and did not want to make a complaint.
The court heard Mr Lloyd was taken home to his father's house where he was urged to get medical attention by his worried family.
He refused help, but instead went to bed while his father checked on him during the night.
Mr Wilson said: "His father kept an eye on Ben through the night but discovered him at about 9.30am unconscious. His father attempted CPR but sadly Ben passed away."
The court heard Webster was arrested by officers later that day before he said to police: "He's dead?"
He said he had been "nine out of 10 drunk" at the time and had delivered a "warning shot" after Mr Lloyd had swung two punches first.
In a victim impact statement, Mr Lloyd's mum Kay Main said: "Ben and Jay knew each other for about 20 odd years since they were six or seven.
"The boys always got on really well, so losing Ben and seeing Jay locked up was almost like I lost both of them."
Ms Main said she did not "hold any malice" towards Webster after believing her son's death was an accident.
Webster, of Senghenydd, near Caerphilly, pleaded guilty to manslaughter.
Judge Tracey Lloyd-Clarke said the pair were "more like brothers" before the horrific attack.
She said: "There is no doubt that Mr Lloyd was very much loved by his family and his friends including you."
Webster was jailed for five years and three months.
Gwent Police referred itself to the Independent Office for Police Conduct after officers were in contact with Ben before he died.
A spokesperson for the IOPC said: "We can confirm that we have received a mandatory referral from Gwent Police in relation to their contact with a man prior to him being found dead in Abertridwr.
"We will now carry out an assessment to determine what further action may be required from us.”
In a tribute, Ben's family described him as "one of life's true gentlemen."
They added: "Ben was so happy and positive all the time, he always walked with a spring in his step. A kind, hardworking and generous man who had a lot of friends. You would struggle to find anyone who had a bad word to say about Ben.
"He leaves behind a very large number of family and friends who will feel his absence forever.
"He was the most amazing son, brother and uncle.
"Ben was always joking around and making light of every situation, he was such a bright star in this world and we are sure he will shine just as bright in the next."
"Ben was so happy and positive all the time, he always walked with a spring in his step."
