Marvin Dickson, 40, was found dead at the north London home of his killer, Dante Forrest, on September 20 last year.
Police discovered his body curled in a bathtub after a neighbour of the defendant alerted the force to a “dreadful smell” coming from his property.
A jury deliberated for about seven hours before they found Forrest guilty of murder on Thursday, following a trial at the Old Bailey.
The victim’s family, sat in the public gallery, burst into tears as the foreman returned the jury’s verdict.
Addressing the defendant, judge Nigel Lickley KC said he would be passing a life sentence.
Mr Dickson was last seen on CCTV footage in the early hours of September 10 walking with the defendant and carrying a takeaway pizza box, the court previously heard.
A pathological examination showed he died as a result of “substantial” blunt force trauma to the left side of his head.
A “blood-stained” pizza box was found in Forrest’s flat suggesting Mr Dickson died soon after the last sighting.
Forrest, of Moselle Avenue, Wood Green, will be sentenced on November 18.
