The trio then headed from the stadium along London Road through Bridgeton, towards the city centre to get a train home.
Shortly after 5pm they passed a group of people standing outside a pub near Bridgeton Cross, including local man Jason Campbell.
Suddenly and without warning Campbell ran up behind Mark, grabbed him round the neck and slashed his throat.
Mark staggered forward diagonally across the pavement and fell beside the gutter.
Onlookers rushed to help and tried to staunch the blood pouring from the gaping wound using anything they could, including clothing, towels and beermats. A young father even gave the blanket from his baby’s pram, but Mark bled to death on the pavement within minutes.
In the immediate aftermath of the attack, Campbell sprinted to his home just a few hundred yards away in Heron Street where his family was having a birthday party for his 12-year-old nephew.
He quickly showered, changed and left – travelling later that night to stay with friends in Greenock.
During the first hours of their murder investigation that evening, police received at least 50 telephone calls naming Campbell as Mark’s killer.
The attack had also been witnessed by other fans, women out shopping with their children and people in cars and buses.
The following day Campbell gave himself up and was positively identified by several witnesses as the man they saw fleeing the scene.
It also emerged that Campbell came from a family with strong Loyalist connections.
In June 1979, his father Colin Campbell, uncle William Campbell and seven other members of the paramilitary Ulster Volunteer Force (UVF) had been sentenced to a total of 519 years for terrorist offences.
Charges ranged from the bombing of two Catholic pubs in Glasgow and furthering the cause of the UVF by gathering arms and explosives.
Bill Campbell, then the UVF’s commander in Scotland, was sentenced to a total of 62 years – and told he must serve 16. Colin Campbell got 57 years, of which he had to do 15.
In March 1996, Campbell stood trial for Mark’s murder at the High Court in Glasgow.
The jury was told that Mark and his two pals were passing a pub in Bridgeton Cross when someone spat beer at them.
The three boys ignored this and carried on walking.
One of his two pals who gave evidence said they had never experienced any trouble before at this spot.
He insisted they did nothing aggressive or anything to attract attention to themselves.
The pal added: “We were just walking along and talking.”
It was at this point that Campbell carried out the murder before running off.
The jury heard how Campbell ran up behind Mark and hurled sectarian abuse before slashing his throat.
A seven-inch wound from his chin to his ear severed the teenagers’ jugular vein and left a 26-yard trail of blood.
Dr Gordon McNaughton, a registrar at Glasgow Royal Infirmary, described Mark’s injuries as “non-survivable”.
A police officer told the jury Campbell was the “only name in the frame” and they had tried to arrest him at his nearby home 45 minutes after the attack.
One witness identified Campbell as the killer at a police officer parade and then in court as he sat in the dock. Two others saw him with a knife before the murder.
One said she got the impression Campbell was looking for trouble because he was standing outside a pub shouting at Celtic fans.
She said she saw Campbell pull something out of his waistband, walk up behind Mark and his two friends, and carry out the fatal attack.
Campbell gave evidence in his own defence and claimed he was at home with his family at the time of the murder and didn’t leave until after 6pm.
He told the court: “I have been accused of something I never done and know nothing about.”
Campbell’s mother Agnes also gave evidence backing her son’s alibi that he was at home at the time of the murder.
However, following seven days of evidence a jury found Campbell guilty, after spending the night in a hotel.
Following the decision, it was revealed that Campbell had a previous conviction for carrying a knife.
Before sentencing, trial judge Lord Sutherland told the 23-year-old: “The victim was 16 years old and this murder was of a particularly brutal nature on an entirely innocent youth, minding his own business and walking along a public street in broad daylight. It was a piece of completely mindless violence.”
As he was led away Campbell gave his family, including his dad and uncle, a thumbs-up sign.
A detective who was involved in the case said afterwards: “This murder chilled the public because the victim could have been your son, my son, indeed anyone’s son.
“He was picked at random and killed for no other reason than he supported the wrong football team.
“What happened shocked people so much that the dogs were barking Campell’s name in the street soon after it happened.
“Our phone was red hot, and each caller named Campbell as the killer.
“The trouble was the Campbell family is so feared in the area witnesses were just terrified to give their names.”
Campbell was initially jailed in 1996 without limit of time.
However, the introduction of European human rights legislation meant the courts had to fix the period he must serve, with a minimum of 15 years set in 2002.
But before this, Campbell found himself at the centre of a political controversy in 1997.
It emerged that he was on the brink of being transferred to Maze Prison, near Belfast, after a request by the Northern Ireland Progressive Unionist Party to the UK Government as part of the then peace process.
There was fury at the idea of Campbell being afforded the status of a “political prisoner” which could have meant an early release from his life sentence under the terms of the Good Friday Agreement.
However, Donald Dewar, then Scotland secretary, intervened and blocked the move.
Later, Mo Mowlam, Northern Ireland secretary at the time, apologised to the Scott family.
In the immediate aftermath of Mark’s murder there was a public outcry over the savagery.
His death also ignited the debate over sectarianism in Scotland and led to a high-profile campaign five years later to wipe out bigotry.
In 2000, Cara Henderson set up the anti-sectarian group Nil by Mouth – supported by both Rangers and Celtic – which still operates to this day.
She had been at school in Glasgow with Mark at the time of the murder and he had been her first boyfriend.
Mark’s lawyer dad Niall Scott and mum Judith set up the Mark Scott Foundation in 1996 to help young people develop their talents.
They also created the Mark Scott Leadership for Life Award to inspire and encourage young people to reach their full potential.
In a rare interview in 2007, Mr Scott said: “Time helps but it doesn’t heal.
“You are left with a sense of incompleteness, of having lost your first child.
“Mark was a spirited, talented sort of guy who was always in the thick of things. He was a leader; he took the initiative and responsibility.”
At the time of his death Mark was the eldest of four siblings and was said to have ambitions to be a sportswriter.
In May 2011, Campbell was released on parole back to Bridgeton where the murder took place.
In an interview three years later, he said he was sorry for the killing, adding: “I’m a dad now.
“I just want to move on with my life and I’m sure his family do too.
“There’s nothing I can say that will change things. There’s nothing I can say that can say enough sorrys to that family.
“The last thing they want to hear is me say sorry.”
Mark’s murder was raised again in an interview in 2016 by the then Lord Advocate Frank Mulholland.
He described Scotland’s history of sectarianism and bigotry as “simply shameful”.
Mr Mullholland then added: “I see the effect it has on our communities. I prosecute cases where people have been killed, maimed and even thrown off a bridge because of it. The appalling murder of Mark Scott in 1995 is the real face of sectarianism and hatred.”