Liverpool fans were caught up in violent clashes with police in Paris, with many tear gassed and bloodied during the Champions League final.
The Reds took on 13-time winners Real Madrid at the Stade de France, just north of the city, on Saturday night.
However, chaotic scenes away from the pitch saw fans with tickets forced to wait in huge queues until the match started.
UEFA said the delay was due to the late arrival of Liverpool supporters, but the club said that was “completely incorrect”.
Footage on social media appeared to show people climbing barriers as crowds built up, and kick-off was delayed by more than 30 minutes.
Police carrying shields and riot gear had moved into the area shortly after 8 p.m.
Supporters showed what appeared to be tickets to officers after a door closed, denying them entry.
Bottles were thrown at the officers who responded with tear gas, leaving some fans with their eyes closed.
The fans who were still waiting to enter were visibly frustrated.
One fan, Carl Noades, 63, told the PA news agency: ‘It looks like there’s only one open door, it’s ridiculous, the game has started and we’re stuck outside .
“It’s a shame, the way they treat us is shocking, there is no organization.”
The tensions outside the stadium were then carried by the young Parisians.
Liverpool supporters said hundreds of locals jeered at riot police, causing the gates to close.
One fan said, “It will be pinned on us, but it has nothing to do with us.
“There are hundreds here causing trouble, they’re not even for the game – it’s chaos.”
Fans argued with ticket agents on the other side of the fence, and beyond the gates some people, including a few wearing Liverpool shirts, were led away.
Other fans flocked to a nearby pub to watch the game.
Nick Smith, 42, told PA: ‘I had a ticket, paid for through the nose, especially the minute everyone was struggling.
“But the total lack of organization means I’m in a pub and not where I should be.”
Liverpool fans with tickets were then admitted to the stadium within hours of queuing and well after the game had started.
Officers used tear gas, batons and shields to force the young residents away from the outside area.
A man was wrapped in a blanket surrounded by rescuers after being caught up in a fight.
Dozens of supporters with legitimate tickets were then allowed entry.
One fan told PA: “I waited in line for four hours, my wife and I have tickets. Appalling.
“I’m devastated, Liverpool fans shouldn’t be held responsible for this.”
A statement from UEFA read: “During the match, the turnstiles at the Liverpool side were blocked by thousands of fans who had purchased fake tickets which did not work in the turnstiles.
“This created a backlog of fans trying to get in. As a result, kick-off was delayed by 35 minutes to allow as many fans as possible with genuine tickets to gain access.
“As the number of people outside the stadium continued to pile up after kick-off, the police dispersed them with tear gas and forced them away from the stadium.”
Liverpool then issued a statement calling for a full investigation into the events off the pitch.
A club spokesman said: “We are extremely disappointed with the stadium entry issues and breach of perimeter security that Liverpool supporters faced at the Stade de France tonight.
“It’s the biggest game in European football and fans shouldn’t have to experience the scenes we witnessed tonight.
“We have officially requested a formal investigation into the causes of these unacceptable issues.”