Barcelona's European campaign came to a disastrous end with a 3-2 defeat against Eintracht Frankfurt at Camp Nou on Thursday - but one of the most intriguing stories to come out of the result was the number dominance of the away fans in the Catalans' own stadium.
Around 30,000 Frankfurt fans cramped into 99,354-capacity Camp Nou arena to watch their side go 3-0 up by midway through the second half and after surviving a late scare with two Barcelona stoppage time goals, progressing 4-3 on aggregate to the Europa League semi-finals.
The noise from the German fans almost made it feel like Barcelona were the away side in their own stadium, with Barcelona's coach Xavi and president Joan Laporta expressing their displeasure at the situation.
Why were there 30,000 Eintracht Frankfurt fans at Barcelona's Camp Nou?
Barcelona have claimed they only allocated 5,000 tickets to Eintracht Frankfurt fans for the match - in line with UEFA regulations which stipulate that at least 5% of the total capacity of a stadium be reserved for the away club.
However, it appears resourceful Frankfurt supporters managed to obtain 25,000 tickets through unofficial sellers and via a resale.
Barcelona have vowed to investigate the situation.
What Barcelona figures have said about the ticket fiasco
Enric Masip, advisor to Barcelona president Joan Laporta, expressed his disappointment in the Camp Nou scenes via his Twitter account.
"Everyone has the right to sell their tickets, but reality makes seeing a Camp Nou with so many rival fans very, very sad," he wrote.
Tothom està en el seu dret de vendre els seus carnets peró la realitat fa que veure un Camp Nou amb tants aficionats del rival fa molta molta llàstima….— Enric Masip (@enricmasip5) April 14, 2022
Barcelona coach Xavi was surprised at the imbalance of support in the stadium and said the club would be investigating the ticket sales.
"I was expecting 70,000 or 80,000 cules (Barcelona supporters) here but it wasn't like that," Xavi told reporters. "The club is checking what happened."
While dismayed president Laporta said he would ensure the Camp Nou is not dominated by opposition supporters again.
"We are worried about the fact that today a big shame happened which can't happen again," he said.
"We have a large part of the information at hand of what happened, we need to time to process this and we will take the appropriate measures but it's shameful what happened."