A young man was beaten to death with a shovel and a plasterer's whisk after one of his alleged killers shouted "I'm the man," a court heard.
Hughie Saunders, 20, died two days after suffering catastrophic head injuries during the fight at Cobham service station on the M25 in Surrey on 26 June.
Simon Barker, 22, and Mikey Coyle, 21, deny murder and are on trial at the Old Bailey.
The prosecution said the defendants were "spoiling for a confrontation of some sort."
Sandip Patel QC told jurors Mr Saunders, nicknamed Quhey, had been returning home from a family wedding in Wales in a Ford Focus with a friend, aunt and uncle, when they decided to stop for refreshments.
Around the same time, the defendants also pulled into the forecourt, travelling in a van loaded with building tools.
As they made to drive off, Coyle and Barker allegedly recognised the victim and turned back, going the wrong way around a roundabout to park in front of the Ford Focus.
They then jumped out and Baker allegedly "squared up" to Mr Saunders as "heated words were exchanged," the prosecutor said.
The brawl appeared to "ignite" when Coyle said something and all three began to fight before moving into the shop, jurors heard. .
CCTV showed the defendants going back to their van where Coyle armed himself with a large shovel and Baker took up a whisk, which he used to inflict a "catastrophic" head injury to Mr Saunders, the court heard.
Coyle allegedly was heard shouting "I'm the man, I'm the man" before taking up his makeshift weapon.
Baker handed himself into police on 29 June, saying he had acted in "self-defence".
Coyle went to police a few days later, and accepted he was at Cobham Services on the day of the fight, but did not say with whom or what had happened, jurors heard.
The trial continues.
