A jury in the Burnie Supreme Court has found Darren Ward Gale guilty of the murder of Noel Joseph Ingham.
Gale sat impassively and barely reacted as the verdict was read out, only slightly shaking his head as the jury exited the court room.
The jury of four men and eight women took just three hours and 50 minutes to reach the unanimous verdict.
Gale had asserted Mr Ingham had died accidentally in the West Ulverstone unit the two men shared, when he collapsed on a fish tank in the living room.
In court, Gale said he feared being blamed for the death and in a panic decapitated Mr Ingham and buried his body in the bushland at Dulverton.
In the nearly seven-week trial, the jury heard evidence from more than 60 witnesses and viewed thousands of photos of the crime scene and the grave site.
In submissions made to Justice Helen Wood after the verdict was delivered, Crown prosecutor Jackie Hartnett said Mr Gale had "a history of violence".