Reece McHutcherson stabbed Murdoch Brown five times in Colchester, leaving him to die in the street.
The attack took place after Murdoch and his brother Robert arrived in the Greenstead area in the early hours of 7 May, 2019.
A court heard Robert had been in debt to a drugs line and planned to speak to someone from the gang to explain how he would pay it back.
He was contacted by Toyn Williams and told to go to Buffett Way, where the br met McHutcherson and Jay Dice.
Robert explained he would repay his £300 debt the following day, but as he did so, Dice and McHutcherson pulled out large kitchen knives.
The brothers fled and Murdoch was stabbed five times. Residents in Buffett Way came to his aid and called emergency services, but the 31-year-old died a short time later.
McHutcherson (pictured below), Dice and Williams stood trial at Chelmsford Crown Court on 8 February and the jury returned their verdicts on Monday 22 March and Tuesday 23 March.
McHutcherson, 20, of Pillow Way, Buckingham, was found guilty of Murdoch’s murder. He had previously admitted being concerned in the supply of class A drugs. He was found not guilty of causing grievous bodily harm.
He was jailed for life, to serve a minimum of 20 years, today, Wednesday 24 March.
Dice, 23, of Mayville Road, Leytonstone, was convicted of conspiracy to pervert the course of justice. He had previously admitted being concerned in the supply of class A drugs.
He was found not guilty of murder and causing grievous bodily harm. The jury were discharged from reaching a verdict on a charge of manslaughter.
Williams, 29, of Winchester Road, Hale End in east London, was convicted of conspiracy to pervert the course of justice and being concerned in the supply of class A drugs. He was found not guilty of murder, manslaughter, and causing grievous bodily harm.
Another runner for the drugs line, Kayley Hodgkinson, 32, of Cedars Road, Colchester, was found guilty of conspiracy to pervert the course of justice. She was found not guilty of assisting an offender.
Dice, Williams and Hodgkinson are due to be sentenced on Monday 29 March.