A 15-year-old boy has been found guilty of murdering a student who was stabbed in north London after a row over throwing conkers.
Steven Grisales was stabbed through the heart after he went to talk to some youths who had been throwing conkers which were still in their spiky casing.
The 21-year-old died the day after the attack in College Close, Edmonton, in August 2011, the Old Bailey heard.
His killer, who is too young to be identified, will be sentenced in June.
Mr Grisales's mother Jasmid said in a statement: "Steven was always loved by every person who had the privilege of knowing him."
"This verdict does not change our lives in anyway because we lost Steven for ever and he is not coming back to us," she added.
After the verdict, Det Insp Richard Beadle said: "Steven did no more than stand up to unruly youths and for that he has lost his life.
"But for the courageous intervention of a local resident, I am convinced the attack would have continued.
"He placed himself in front of Steven whilst the youth continued to try to stab him.
"The defendant's arrogance and contempt for others belies his age."
The teenager blamed another youth for the stabbing, but was identified from his distinctive clothing on CCTV.
He claimed architecture student Mr Grisales had over-reacted and tried to hit him with a skateboard.
But Andrew Edis QC, prosecuting, told the jury: "This was a sudden, unnecessary killing as a response to a confrontation which took place in the street, which was about nothing very much.
"It was about throwing some conkers."