Two men have been given life sentences for shooting a father of four dead after a "trivial argument" in a queue at McDonald's.
One of the murderers told the deceased "you're not so hot now" after he had fired three shots at the victim.
Horace Campbell, 28, and Liam Douglas-O'Callaghan, 18, were found guilty of murdering Devon Scarlett, 32 at the Brixton branch in South London.
Old Bailey judge Richard Hawkins said the row had escalated in half-an-hour to the execution of the father of four.
He jailed Campbell for life with a minimum term of 32 years. Douglas-O'Callaghan was ordered to be detained during Her Majesty's Pleasure with a minimum term of 18 years.
Judge Hawkins told them: "The two of you quickly despatched Devon Scarlett without mercy."
Scarlett and Campbell got into an early morning spat involving others at the fast-food restaurant in April last year.
They were escorted outside by security guards but the row carried on and the two strangers agreed to meet in a nearby street for a shoot-out, said Bobbie Cheema, prosecuting.
Campbell called Douglas-O'Callaghan to bring his "thing", or gun, a retrial was told.
Scarlett appeared to make a similar call but no actual call was made.
Cheema said: "Horace Campbell was determined to avenge the perceived lack of respect that Devon Scarlett showed him.
"Devon Scarlett acted with foolish bravado, behaving like a tough guy, but whatever he said and did, he was not armed."
Campbell, who had been drinking, followed Scarlett into Marcus Garvey Way and fired three shots, two of them hitting the victim.
Campbell said: "You are not so hot now", before walking away.
Scarlett, of Croydon, who was born Raymond Mitchell, died a few hours later in hospital.
Campbell, of Anerley, and Douglas-O'Callaghan, of Tulse Hill, both south London, denied murder.
The court heard that Scarlett had become involved in "someone else's argument" in McDonald's at around 6.30am on April 17 last year.
Outside, Scarlett was heard saying he had been shown disrespect, and Campbell said Scarlett was "going to be shot in the head".
When people tried to intervene, Campbell told them Scarlett had been "too disrespectful and was going to be shot in the head" and would be "filled up with lead".
A woman had heard them agreeing to meet in the nearby street, "effectively for a shoot-out", jurors were told.
Detective Inspector Henry Lindsley said: "Unbelievably, Devon Scarlett's murder was triggered by the most minor of incidents that Horace Campbell chose to involve himself in.
"His arrogance and obvious disregard for life is evident when, even after Scarlett walked away from him, he continued spoiling for a fight."