David Swaby inflicted more than 50 injuries on Hassan Ghafar during the early hours of February 7 this year.
Mr Ghafar, 22, suffered significant knife wounds – one of his arms had been severed – during the frenzied attack across a number of rooms in Holly Road, Handsworth.
Swaby fled through a kitchen window when officers arrived, but he was quickly chased down and arrested. The 34-year-old claimed he had been defending himself but offered no consistent version of events around what happened.
After searching the address, West Midlands Police officers found a number of items including knives, scissors, rolling pin, poles and a dumbbell containing Mr Ghafar's blood.
Swaby, of Holly Road, in Handsworth, was convicted of murder following a trial at Birmingham Crown Court. He was remanded in custody ahead of sentencing on October 15.
Detective Inspector Ranj Sangha, who led the investigation for West Midlands Police, said: "This was a brutal and prolonged attack on Mr Ghafar who sustained blows across his body along with significant stab wounds.
"No one should be put through such an ordeal and this has been a harrowing experience for Mr Ghafar's family, who have had to live through what happened to him during the trial.
"We may never truly know what led to the events in Holly Road. We recovered CCTV showing the pair arriving at the address in the early hours of the morning with no hint of anything being untowards between them.
"Tragically, nothing can ever be done to bring Mr Ghafar back and our thoughts will always remain with his loved ones."