A 15-year-old wept as he was detained for 13 years for stabbing a boy to death in an ambush near London's world famous Portobello Road.
Fola Orebiyi, 17, was expecting a fist fight but ended up being knifed in the neck and back near the street market in Notting Hill, west London. He was pronounced dead an hour later.
His killer, who cannot be named because of his age, stabbed him twice on the evening of July 3 2016 over a trivial row.
The teenager ran away, leaving his collapsed victim to bleed to death in the street, before disposing of the blade and clothes he was wearing.
He was sentenced to detention at Her Majesty's pleasure, the equivalent of life imprisonment, with a minimum of 13 years for murder at the Old Bailey on Friday.
The public gallery was packed for the hearing and the victim's family sat in silence as the details of Fola's final moments were retold.
The defendant bowed his head and wept, wiping his eyes on his sleeve.
Fola's mother Yinka Bankole described her son as "a vibrant and intelligent young man, with a bright future ahead of him" who was looking forward to going to university to study maths and physics.
"We are still trying to process the fact that our beloved boy is no longer with us," she said in a statement on behalf of the family.
Fola's young brother said he was his best friend and asks for him every day, she added.
"He knows Fola is in heaven now and not coming back but still asks for him all the time," Ms Bankole said.
"I feel like this tragedy could so easily have been prevented."
The victim's father Michael Orebiyi said he cannot find "rest and peace" and that "being happy doesn't feel right anymore".
"Each time it hits my heart it's devastating. Fola was my son and didn't deserve to die in the way he did," he added.
Judge Anthony Bate said he was moved by the statements from Fola's family describing their "profound sense of loss at this talented young man's life being tragically cut short".
He told the young defendant that his carrying a knife in a public street was a "disturbing feature of the case".
One of Fola's friends had a fight with the 15-year-old defendant, exchanging insults in the weeks before the killing.
On the night of his death, Fola and his friends ran into the defendant and his friends near Portobello Road after watching a football match together.
He and his friends agreed to have a fight but he did not know that his opponent was armed with a knife, which he used to ambush his victim, singling him out and stabbing him to death within seconds.
Lisa Wilding QC, defending, said the stabbing was "a tragic, senseless and needless death which arose because of the most trivial of circumstances".
She described the defendant, who is the youngest of 11 siblings and comes from a dysfunctional family, as a vulnerable young boy.