Azeem Issa pulled out a blade he regularly carried in the waistband of his trousers and plunged it into his 28-year-old friend Sahil Roy's shoulder and neck during an unprovoked attack on April 10 this year.
Issa, described as a self-styled gangster, was found guilty of murder after a three-week trial at the Old Bailey court in London.
Judge Johannah Cutts jailed him for life with a minimum term of 20 years and issued a warning to others who habitually carry knives, the Evening Standard reported.
The court was told that Issa had first fallen out with Roy two days before the murder when he was teased for losing at a game of Fifa on the Playstation.
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In the following days, Issa - also known as Ricardo - grew increasingly agitated with his friend who was dodging his calls and refusing to answer the front door.
Enraged, he pushed Roy, pulled out the concealed knife and proceeded to stab him in the shoulder and neck before he fled the scene.
Roy's parents, brother and sister were called and rushed down from the flat to find him collapsed and bleeding. Police arrested Issa at his home address later that evening and charged him with Roy's murder on April 12.
Investigating officer Detective Chief Inspector Diane Tudway, of Scotland Yard's Homicide and Major Crime Command, said: "This was a brutal attack which saw a young man, who was due to be married, lose his life and his family have been left heartbroken. Our thoughts are with Sahil's family and friends and we hope that today's conviction will give them some peace."