38-year-old Barry Bowyer has been found guilty of murdering TV actor Gary Suller at Cardiff Crown Court.
The 45-year-old, who was best known for his roles in Casualty and Doctor Who, was found dead in his home in Pontnewydd, Cwnbran, last year. He was tied up and beaten to death.
Bowyer is due to be sentenced later today.
An actor in Dr Who and Casualty was beaten to death by a jealous love rival, Cardiff Crown Court has heard.
Televsion extra Gary Suller, 45, was allegedly killed in a bitter love triangle over 27-year-old Katie Gilmore - and the murder trial jury heard he wanted to marry her.
But the court heard she had another lover, Barry Bowyer, who "hated" Gary because he was afraid of losing her.
Bowyer, 38, allegedly broke into Gary's terraced house in Pontnewydd, near Cwmbran, and lay in wait for him to come home.
Prosecutor Peter Davies said: "Barry Bowyer and Gary Suller were not strangers to each other - they where both in love with the same woman.
"It was an prolonged, unrelenting and brutal attack where he inflicted gross and fatal injuries."
Father-of-two Gary appeared in Doctor Who, Casualty and other TV dramas often as a policeman or prison officer.
Bowyer, of Croesyceiliog, near Cwmbran, denies murder but admits burglary and manslaughter claiming he killed Gary in a "momentarily lapse".
The trial continues.