A man has been jailed for life for stabbing his girlfriend's ex-partner to death after he answered the door.
Mark Fisher, 33, was stabbed at his home in Accrington, with one of the blows fracturing a rib, police said.
Joseph Hindle, 46, was convicted of his murder at Preston Crown Court and told he must serve at least 27 years.
His girlfriend, Louise Henwood, 34, who goaded him into the attack, earlier admitted manslaughter and was jailed for 13 years.
Lancashire Police said Henwood had sent Hindle to rob Mr Fisher, who was her former partner, as she believed he could have some cannabis.
Henwood goaded Hindle by telling him Mr Fisher had been violent to her in the past, the court heard.
Hindle arrived at Mr Fisher's home on Edleston Street shortly after 12:30 GMT on 19 January 2020.
Mr Fisher was attacked when he answered the back door, with one of the blows "delivered with such force that it fractured a rib", police said.
He died an hour later.
Hindle and Henwood, of Woodside Road, Accrington, were both arrested and Hindle charged with murder and Henwood manslaughter.
Hindle, who had denied murder, was found guilty at Preston Crown Court on Friday after a trial.
Henwood pleaded guilty to manslaughter at an earlier hearing.
Det Ch Insp Zoe Russo said: "Hindle attacked Mr Fisher in his home...he unleashed extreme violence that was far in excess of anything needed to carry out a robbery.
"There can be no doubt that the intention was to do him really serious injury."