Pic:William Livesley's mother said he would "always be my baby"/bbc/wp
Crime reporter(wp/bbc):
A 21-year-old man has died in what police said was a "horrendous attack".
William Livesley was taken to hospital after the assault on Bickershaw Lane in Abram, Wigan, on Friday night, but died the next day. Greater Manchester Police are treating the death as murder.
Mr Livesley's mother Sylvia described her son as "one in a million".
Post-mortem tests showed Mr Livesley died of a head injury. Two men arrested in connection with the attack have since been released.
A 57-year-old man arrested on suspicion of conspiracy to commit attempted murder was earlier released while inquiries continue.
A 38-year-old man arrested on suspicion of attempted murder has since been released with no further action.
'Destroyed our family'
Mr Livesley's mother said her son was "idolised" by his younger relatives.
"Billy was one in a million. Those responsible haven't just killed my son, they have destroyed me and our entire family.
"We will always love him and he will always be my baby."
Local football team Abram FC posted a tribute on Facebook, saying: "You were brilliant on the pitch and a brilliant lad off the pitch."
Det Ch Insp Stuart Wilkinson said: "This was a horrific attack on a young man who has tragically lost his life at the hands of others.
"We have specialist officers supporting Billy's family who have understandably been left completely devastated by this and my thoughts are very much with them at this incredibly difficult time."
He thanked local residents for their assistance and support, and urged anyone with information to contact the force.