A 14-year-old girl "set up" a schoolboy to be stabbed to death after a row over football, a court has heard.
The Old Bailey was told the girl called her 16-year-old boyfriend to a housing estate in Brixton, south London, where he killed Junior Nkwelle, 15.
Jurors heard Junior and his friends had been playing football on the Loughborough estate in September last year when an argument broke out.
The girl and her boyfriend, who is now 17, deny murder.
They cannot be named for legal reasons.
The court heard Junior was stabbed in the chest after the older boy arrived on a bus and started fighting with him.
The knife cut his heart and a lung and he died at the scene, jurors were told.
'Should be punished'
Jonathan Turner, QC, prosecuting, said it was likely Junior and his alleged killer did not know each other and there was no quarrel between them.
He said: "He [the defendant] had been telephoned by his girlfriend and told to come to the estate to teach Junior Nkwelle a lesson.
"There had been an argument between her friends and Junior's friends whilst the football was going on.
"She thought that Junior had insulted her or been less than respectful to her.
"She was very angry and determined that he should be punished - indeed stabbed - to put things right."
Mr Turner told the court the girl had called her boyfriend and was heard to tell Junior that she had arranged for somebody to come and stab him.
He said: "He [the defendant] was encouraged and requested by her to come and do this."
Mr Turner said the argument might have been because the boys were thought to be playing too close to flats, or that the girls were walking over the pitch.
"Whatever it was, it seems to have been stupid and trivial and completely unnecessary," he said.