The trial of a man accused of beating his wife's lover to death in a 'brutal and sustained' attack has begun.
Ian Anderson, aged 54, has denied the murder of Neil Roberts at his home in Queen Street in Castletown in 2013.
Prosecutor Peter Wright KC said the pair had had an argument that became violent, resulting in the death of 60-year-old Mr Roberts.
Douglas Courthouse was told the case was a retrial, the BBC has reported.
Deemster Graeme Cook said a previous conviction had been quashed on appeal as psychiatric evidence was not properly put before the original jury.
The court heard Mr Roberts, a gardener from Ballabeg, had been having an affair with Mr Anderson's wife for several months before the attack.
During this time Mr Anderson was periodically away from home as he was working for a firm in London.
On the evening of November 30, the two men met for a drink at the Bay Hotel in Port Erin before travelling back to Mr Anderson's home.
Mr Wright said the argument broke out at about midnight before Mr Anderson proceeded to beat "the living daylights" out of the older man.
A post-mortem report found the injuries were "very severe", with evidence of repeated forceful stamping or jumping.
The court heard Mr Anderson had made and received numerous calls with friends and family before calling 999 at about 01:00 GMT.
A recording of the call was played where he said he acted in self-defence, a claim the prosecution said he "lied to hide the awful truth".
The court heard Mr Anderson would put forward a defence of manslaughter by provocation or by reason of diminished responsibility.
However, Mr Wright said Mr Roberts' injuries "tell their own terrible tale" of a man who killed his rival in an "unbridled fit of anger".
The trial continues.