Northampton teenager Liam Hunt died from five stab wounds, including a cut to his neck that was seven centimetres deep, a court has heard.
Seven young men are on trial at Northampton Crown Court charged with the 17-year-old's murder in February last year.
Today (February 6), the court heard how the alleged attack was fueled by revenge after an earlier fight between Liam and one of the defendants, James Dodd, 19, from Wellingborough.
And after the "violent and shocking" group stabbing, the jury were told that some of the defendants were reportedly seen in a town centre McDonalds hours later "bragging and joking" about what had just happened, possibly unaware of Liam's death.
Prosecutor John Lloyd-Jones said: "On the afternoon of February 14 last year, the seven defendants in this case went looking for Liam Hunt and his friends. Their motive was revenge.
"Two days before, in the early hours of Feb 12, there had been an incident in Northampton town centre involving Liam Hunt and his friends and James Dodd. There had been a fight and Dodd came off second best. Dodd developed a grudge."
The court heard how Dodd messaged his friends the next day about the fight. He texted one friend and said: "My boys will stab them when I find them".
On February 14, Dodd bumped into Liam in St George's Row, off Barrack Road, and was chased off by Liam's friends.
Mr Lloyd-Jones said: "It was those two events that were the catalyst shortly thereafter for the murder of Liam Hunt.
"At about 5pm, these seven defendants found Liam Hunt and his friends in St George’s Street. There was a violent confrontation. Liam was punched, kicked and stabbed five times, including a fatal wound in the right side of his neck. And Liam Hunt died about an hour later in hospital."
The gang was reportedly armed with a brick, electrical flex and three knives when they attacked Liam.
CCTV footage tomorrow will show how the defendants "scattered" after the stabbing and tried to get rid of their weapons.
The seven defendants are Aaron Joseph, 21, from London, James Dodd, 19, from Sentinel Road, Northampton and Derice Wright, 18, who lived in Lutterworth Road, Abington at the time of his arrest.
There is also Kane Allaban-Hamilton, 18, from Pleydell Gardens, Delapre, and Lee Warren, 18, from Queens Park Parade, Queens Park.
Two 17-year-old boys are also on trial and cannot be named because of their ages.
It is alleged Allaban-Hamilton, Aaron Joseph and one of the unnamed boys were the ones who stabbed Liam, with Allaban-Hamilton delivering the seven-centimetre wound to his neck.
The trial continues.