Around a minute later, Wilson punched Mr Imnetu five times in the head, continued to repeatedly punch him while he was on his hands and knees, and then kicked him in the head.
Omar Wilson repeatedly punched and kicked Mussie Imnetu during an altercation outside a restaurant in Queensway, west London, on 26 August last year.
Sentencing Wilson to a minimum 18 years, Judge Philip Katz said Mr Imnetu's "brutal" killing was "abhorrent".
CCTV footage was played in court during the trial showing Wilson approaching Mr Imnetu and headbutting him.
Mr Imnetu's wife, Linda, described her husband as "respected, admired and loved" in a pre-recorded victim impact statement played in court.
