Levi Westhead, 18, stabbed 50-year-old Mark Webster at the family home on Carsluith Avenue on July 23 last summer.
Westhead stood trial at Preston Crown Court and today the jury unanimously found him guilty.
CCTV shown in court from the afternoon of the murder showed Westhead outside his ex-girlfriend’s workplace on Albert Road Blackpool. He was seen waiting for her and then trying to speak to her following his relentless messages and phone calls which had totalled nearly 300 the day before the murder.
The jury were told how Westhead had arrived at the Webster family home later the same evening armed with a knife. He knocked on the front door demanding to see his ex-girlfriend, but Mr Webster had refused to let him inside.
The defendant then made his way around the back of the house and gained access to the back garden. Mr Webster has gone outside at this point and a scuffle has ensued ending in Mr Webster receiving the fatal stab wounds. A kitchen knife, confirmed as the murder weapon, was found at the scene.
Further CCTV footage showed Westhead walking along nearby Canterbury Avenue towards the property in the minutes before the incident and then running back away from the property in the moments after.
Evidence also included how Westhead had sent text messages and made a call to his grandmother, after fleeing the scene, in which he is reported to have said: “I’m sorry, I’m sorry, I’ve hurt somebody with a knife, I was so angry.”
After just two hours of deliberation, the jury returned a unanimous guilty verdict.
Westhead will be sentenced on March 17.
Det Chf Insp Jane Webb from Lancashire Police Force Major Investigation team said: “This is an utterly tragic case where a much-loved husband and father was merely protecting his family when he was stabbed to death.
“Sadly, this verdict provides no relief from the dreadful loss that Mr Webster’s family and friends have suffered. They have remained incredibly dignified throughout this investigation and my thoughts remain with them at this desperately difficult time.”
Tom Snape for the CPS said: “Levi Westhead is a controlling, violent and angry young man. His actions on that night has had devastating consequences to all who knew and loved Mark Webster.
“Westhead denied murder, but we presented evidence to the jury proving that he had intended to cause serious harm to Mr Webster when he stabbed him numerous times with the knife he had taken with him. After careful consideration of that evidence, the jury found him guilty of murder."
In a statement the family said: “Despite the conviction it will not bring back Web or ease the pain of him not being with us.
"It does however give us some peace of mind knowing that Levi Westhead will be where he belongs for the term of his sentence. His death was so unnecessary. We would like to thank the police, the prosecution team and the jury for bringing us this justice.”