Josh Price, 21, was knifed five times in an ambush by David Watkins, aged 27, who had lured him to a meeting where he said he wanted to buy cannabis.
Mr Price was attacked within seconds of reaching the rendezvous in Treynham Close, Stowlawn, in September 2014.
Watkins, formerly of Clem Attlee Court, was found guilty by a jury today and jailed for life.
A second man, Jake Henson, 21, of Wellington Road, Bilston, was cleared of the same charge.
Prosecutor Mr James House QC told the trial at Wolverhampton Crown Court: "The motive for the murder is not clear. Whether it was to rob him of his possessions, phone or drugs is not known."
There was a suggestion that Watkins had been involved in a dispute with the victim several days earlier.
Judge James Burbidge QC told Price this afternoon: "I am sure you took the knife along to the scene, but why you did that is not clear to me.
"Neither I nor the jury have been told the full truth of the purpose of your meeting that night."
Watkins had indicated he was willing to plead guilty to manslaughter on the grounds of diminished responsibility, after claiming he had heard voices in his head telling him to launch the attack.
But this was rejected by the prosecution. After hearing evidence from psychiatrist, the jury rejected his claims.
Det Insp Warren Hines said: "We had a very clear picture of the events of that evening from CCTV cameras in the area and witness accounts, but the offender had dressed himself in dark clothing and covered his face, so we had difficulty in identifying him.
"Then at the end of October Henson told his mother a distorted version of the truth about his involvement in Joshua's death. His mother, who knew Joshua and his family, was put in a difficult situation, but did the right thing and reported what she knew at a police station.
"Henson and Watkins were arrested a short time later."
"We will never know the reason for the attack on Joshua, but the tragedy is that Joshua had his whole life ahead of him with his partner and his son and this was cruelly cut short."
Speaking after the tragedy, Joshua's girlfriend Megan Campbell, said: "I loved Josh loads…we have been together for four years. He was a great father and partner and will be deeply missed."