Police believe the killer of a promising young boxer lay in wait while he visited a friend.
Eamonn Magee Jnr, son of former WBU welterweight champion Eamonn Magee Snr, was stabbed multiple times in the garden of the house at Summerhill Park in the Twinbrook area of west Belfast.
The attack, described by police as vicious, happened as the 22-year-old engineering student went to check on a pizza delivery during the early hours of yesterday morning.
Detective Chief Inspector John McVea, who is leading the murder hunt, said: "Nobody would have known that Eamonn would have been coming out of the house to look for the pizza delivery, therefore we believe that the person was lying in wait for Eamonn as he would have come out of the house."
A 32-year-old man remains in police custody being quizzed about the killing.
DCI McVea described the suspect as a "strong line of inquiry" but declined to comment further on whether he knew Mr Magee or the friend he was visiting.
The knife used in the killing is believed to have been stolen from a property nearby which has been searched by police.
DCI McVea added: "We are particularly interested in the time between 1.30 in the morning and 3am.
"We believe the attack happened at 2.30 in the morning. But we believe the person may have been in the area for some time prior to the attack.
"Eamonn sadly has been attacked instantly as he has come out the back door into the garden.
"He has been stabbed a number of times."
Residents who were alerted to a disturbance tried in vain to save Mr Magee who succumbed to his injuries shortly after arriving at hospital.
A number of floral tributes had been left at the scene in the staunchly nationalist estate on the edge of West Belfast.
The senior officer said the entire Magee family had been left devastated by the tragedy.
He said: "Obviously, as you would expect, they are devastated by this.
"Eamonn was so popular and had such a promising future ahead of him. He was so young. He won a number of fights in the early stages of his boxing career. He had a promising future and it is particularly sad for that to have been taken away so needlessly."
Eamonn Magee Snr was known as the Terminator during his professional career, and he also enjoyed Commonwealth success.
Among his most high profile fights was the 2002 sell-out bout against ex-world champion Ricky Hatton in Manchester.
Since retiring he has worked as a trainer at the well-known Breens Gym in Belfast.
The world of boxing has expressed shock at the murder.
Former World champion Barry McGuigan used Twitter to convey his sympathies.
He said: " Dreadful news about Eamon Magee Jr, deepest sympathies to his family."
Ricky Hatton also tweeted: "Just been sickened with the news Eamonn Magee Jnr has been stabbed to death.My love goes out to Eamonn snr.Thinking of you my old friend.x
Meanwhile, Belfast's close-knit boxing community has also been left reeling.
IBF super-bantamweight champion Carl Frampton said on Twitter: "Absolutely terrible shocking news about Eamonn Magee Jr. May he RIP."
Double Olympic medallist Paddy Barnes added: "RIP young Eamonn Magee, murder by scum in Belfast last night."
Well-known trainer John Breen described Mr Magee as a "quiet gentleman".
Mr Breen, a family friend for over a decade, said: "He was a lovely wee lad. He always took on board everything you said. He was a genuinely lovely lad with a promising future ahead of him.
"His father is still in shock. They all are. No one could believe it when they heard the news. It's a terrible tragedy."