A 15-year-old boy has insisted he did not mean to harm a 17-year-old who died after suffering a single stab wound.
Tyrone Hayman was pronounced dead in hospital shortly after suffering the injury at his flat in Bedminster, Bristol, on December 14.
Bristol Crown Court heard Tyrone and the boy, then aged 14, had been arguing over a phone charger just before 1.30pm.
The boy, who cannot be identified due to his age, denies a charge of murder and is on trial at Bristol Crown Court.
He told jurors he had been holding the knife when Tyrone was injured but did not have any intention to harm him.
The boy said Tyrone unplugged his phone, which had been charging, in order to charge his own phone.
He described how Tyrone threw his phone to the floor and so he grabbed Tyrone's phone and put it under the sofa.
"I picked up the knife and said to him 'Oi, come here," the boy told the court.
"He looked up and giggled like 'what?'. The knife was in my right hand. He rushed towards me."
The boy said Tyrone then backed away and he saw blood appear on his clothing.
"I could see shock on his face and what appeared to be blood on his top," he said.
The boy claimed that, earlier that day, the pair had been "play-fighting".
Tyrone was holding the knife when the boy suffered a small "nick" to his arm, he told the jury.
He said he was "copying" the older boy when he later picked up the weapon before Tyrone was injured.
Tyrone then ran out to the street and asked people to call him an ambulance, which arrived a short time later.
The boy followed him out and was challenged by a man, who asked whether he was responsible.
"To be honest, I was a bit tearful. I was upset and quite shocked," the boy told the court.
"There was someone there saying 'you stabbed him' and I panicked and got on my bike. I didn't know how to react."
The boy, who described himself as "worried and scared", cycled to his family home and was later arrested.
Dominic Thomas, representing the boy, asked: "You said it was a total accident. Do you stand by that?"
The boy replied: "Yes."
Tyrone was taken to Bristol Royal Infirmary, where he was pronounced dead a short time later.
A post-mortem examination found he died from a single stab wound to the left side of his chest.
The trial, which is expected to conclude next week, continues.
