Three gang members were facing life sentences today for stabbing a youth 24 times in 45 seconds.
Daniel Graham, 18, was attacked with knives and a broken bottle in front of horrified passengers as he jumped off a bus.
Mr Graham was helped back on to the 176 bus by passengers in January last year but died from his injuries, the Old Bailey heard.
Jordan Williams, 17, Colin Aghatise, 16, and Lennie John, 24, all from south London, were found guilty of murder.
They were remanded in custody for sentencing tomorrow.
It was the second time that Williams had been accused of murder in a month.
He was acquitted in December of killing a youth who was shot in south London during a gang attack four weeks before Mr Graham's death.
Judge Timothy Pontius lifted an order banning identification of the two youngest defendants.
He said it was justified "in the context in which Daniel Graham was slaughtered in a vicious attack during which he suffered 24 knife wounds."
Duncan Penny, prosecuting, said trouble flared up at an under-18s event at Dulwich Hamlet Football Club in south east London earlier in the evening.
He said a row broke out between Mr Graham's friends and another group of youths.
"Daniel's group was punched and knives were produced and it appears a firearm was discharged and at least one shot was fired," said Mr Penny.
"Daniel's group fled the party and their escape route took them past East Dulwich railway station. They were pursued by members of the defendants' group."
Mr Graham had tried to take refuge on the double-decker bus before changing his mind and jumping off.
But he was attacked in front of passengers by a large group of youths who subjected him to "a volley of punches, kicks and stamps" to the body and head.
Mr Penny said CCTV on the bus showed the time of the attack as 12.09am.
"It lasted in the region of 45 seconds," he added. "In that short period he had received 24 stab wounds, having been descended upon by a group of murderers."
Passengers made the driver drive off while Mr Graham, who was covered in blood, was laid across two seats by a nurse and her sister.
After seeing some of the attackers at the next stop, the bus drove on until police and an ambulance reached it in Lordship Lane.
Williams, who was said to be a member of the Peckham Boys gang, and John were identified by a youth who had viewed them singing a rap on YouTube.
DNA belonging to Aghatise was found on a broken bottle with Mr Graham's blood on it.
Mr Graham had gained seven GCSEs and was doing business studies. He did voluntary work for the NSPCC children's charity in his spare time.
His mother Stephanie said in an impact statement to the court that she had been devastated by his death.
She added: "Everyone loved Daniel. He was instantly likeable to all who knew him."