Deonte Mowatt-Slater was found dying in Islington, north London, in the early hours of October 22 last year, and died at the scene of the crash.
Francie McCarthy, 22, of Islington, is standing trial at the Old Bailey, accused of murdering Deonte.
Prosecutor Edward Brown KC told jurors on Monday: “The police and ambulance services were called to what was immediately thought to be a road traffic collision involving a youth on a moped who had, it was then believed, driven into a lamppost.
“Deonte had plainly been very badly injured – somehow.
“He was in a grave condition with very few signs of life.
“It transpired, however … that he had been stabbed to the front of his neck.
“Soon it was discovered that he had been stabbed twice, in fact, he had suffered another stab wound to his chest.
“He very quickly deteriorated and despite all the efforts of the ambulance service and the specialist medical teams who quickly arrived, he could not be saved or brought back to life.”
Deonte was pronounced dead at 1.16am, the court was told.
“He had been killed,” Mr Brown added.
“The stab wound to the neck passed through the right carotid artery and subclavian arteries.
“The second and separate stab wound to the chest passed into the left lung.
“His death was not caused by any collision with the lamppost, which may itself have been as a result of Deonte losing consciousness as he rode from the scene of the attack.”
The prosecution alleges that McCarthy crossed paths with Deonte in Courtauld Road, Islington, that night, and that an altercation ensued during which Deonte was stabbed twice before riding off and crashing on the same street.
Emergency services were called shortly after midnight by Rose Galugbo who was getting home when she heard the revving of an engine followed by a loud crash.
“She went out to see what had happened and found Deonte on the ground,” Mr Brown told the jury.
“She was the only person on the street at the time.
“Deonte was, in those moments, groaning and just moving – but very soon fell silent.
“She thought, understandably, that the victim had crashed his moped.
“It was clear to Ms Galugbo that Deonte was bleeding – she saw blood seeping out as soon as she went to him.”
Nel Richards heard two boys or men shouting before the crash, the court was told.
From her window, she saw a person wearing grey jogging bottoms running away, who the prosecution alleges was McCarthy.
CCTV footage from the time of the incident was also played to jurors, in which loud revving is heard before a moped is seen travelling fast down the road, then disappearing out of view.
A loud bang is heard and a voice is then heard shouting “Come here!” as a man in grey jogging bottoms appears running down the road, apparently chasing after the moped.
McCarthy denies one count of murder.
The trial continues.
