A police source said: "Our understanding is an argument started after one of the youths said something to the victim's girlfriend and a female pal that upset them.
"The British boy was stabbed during a brief fight. He fell to the ground feeling dizzy."
Mr Azar, whose dad is Spanish, was taken to hospital after the attack in posh Puerto Banus on the Costa del Sol. The keen footballer lives nearby and attends a private school.
Police were yesterday hunting five people over Friday's incident. Mr Azar is expected to fully recover.
