Tavares-Gaiete, of Ilford, east London, was found guilty of the murder following a retrial at the
The victim, known as Charlie, was fatally stabbed in the chest at Ashton Playing Fields outside Woodford social club in January last year.
He had been attending a friend’s 16th birthday party on the night he was killed.
Tavares-Gaiete fled police after the stabbing, prompting a manhunt.
He was found and brought into custody three weeks later.
The two teens had once been friends, and had even gone to the same school, but had a falling out towards the end of 2015.
Speaking on the case, Detective Inspector Jamie Stevenson said the fact Tavares-Gaiete showed up at a party with a knife proved he was looking, or at least anticipating, trouble.
He said: "At 17 years old he is now a convicted murderer, who has shown no remorse for taking Charlie's life.
He immediately went on the run to try and evade the police and still to date has not admitted murdering Charlie or explained why.
"In fact, he has tried to blame Charlie, claiming he acted in self-defence."
In May last year, Tavares-Gaiete claimed Charlie was a member of a gang whose other members had beaten him up twice.