An excited schoolboy treating himself to a new PlayStation controller was barbarically executed in the street after being mistaken for someone else.
Ronan Kanda was attacked within yards of his family's home in Wolverhampton.
A sword-wielding thug sprinted up behind the teenager, who let out a spine-chilling scream as the weapon was shoved 20cm deep into his body.
His killer then drove the huge blade through him a second time, a court has heard.
The youths, both 17 and unable to be identified because of their age, have been convicted of his murder at Wolverhampton Crown Court, BirminghamLive reports.
Two other men, Joseph Whittaker, 18, and Josiah Francis, 20, were found not guilty of murder.
Jurors were told the killers fled the scene in the Black Country, with hopes of evading justice forever.
But their escape was short-lived as both boys were later arrested and have now been convicted. The youths will be sentenced on 13 July.
Just one of the boys was to blame for delivering the blows as the second teenager only brandished his weapon and never used it.
But the pair were convicted on a joint enterprise basis over Ronan's heartless slaughter.
A five-week murder trial heard how football fan Ronan had dropped by at a friend's house to buy a PlayStation controller for £5.
His now-devastated dad recalled offering Ronan a lift.
But with no clue what lay ahead, the teenager decided to walk. Making his way back to his Wolverhampton home, Ronan put on his headphones and innocently listened to music.
He was just yards from the doorstep of his family home in Mount Road, Lanesfield, when his killer pounced on him from behind, with no time to defend himself. The powerless boy screamed out in distress - a sinister moment captured on CCTV footage and repeatedly played to the court, with audio.
But Ronan's cry for help was in vain as he collapsed in the street while his killers left him for dead. He could not be saved and died at the scene on the evening of June 29 last year.
Jurors took just over two hours to convict the two youths of murder. They now face life behind bars and will discover their fate on July 13.
Two men also stood trial alongside the boys. Josiah Francis, 21, of Westcote Avenue, Birmingham, and Joseph Whittaker, 18, of Raven Hays Road, Birmingham, were acquitted of all charges.
Both youths tried to defend their supposed innocence during the murder trial, each telling jurors Ronan was never the intended victim. Instead, they told how they had wanted to "scare" a boy who owed one of them money.
The sword-wielding killer claimed it was all an "accident" and he "felt terrible" as soon as he discovered the mistake he had made. The 17-year-old only wanted to "poke around" the sword, he insisted.
It was not until the second of two stab wounds had been inflicted that he not only noticed the blade had made contact but that it was Ronan he had wounded. The other youth claimed he was left "sad and angry" after discovering Ronan was stabbed in error.
He told how he had lent cash to a boy so he could buy a Fiesta and wanted to "scare" him into handing back the money. But denied he was 'in it together' with his accomplice.
Jurors heard how the 17-year-old who delivered the blows collected a Ninja sword set and a large machete from a post office on the day of Ronan's death after buying it online. He had confessed during cross-examination that he would order what the prosecution alleged were "lethal weapons" with a false I.D to sell them on as a way to "make money".
But he denied having a "fascination with knives".
The two youths plotted to confront the boy who owed the cash before travelling in a red Vauxhall Corsa to the scene of the crime.
