Plane crisis summits, misleading team sheets and an indifferent owner who thought the game was over: the secrets behind football’s greatest comeback as Barcelona shocked the world by beating PSG 6-1.

It was the most surprising comeback in Champions League history. It cost Unai Emery his job, sent striker Edinson Cavani to therapy and meant referee Deniz Aytekin was never able to officiate another knockout match. Tonight could serve as the perfect inspiration for Paris Saint-Germain.

Now it is the French who need to come back, losing 3-2 in the first leg. In March 2017, they won the first match 4-0, but Barcelona did what no team had done before and overcame a four-goal deficit with a 6-1 victory in the second leg.

Barça attributed its comeback to three factors: the leadership of Luis Enrique, who was then Barça coach and is now PSG coach; the raucous Camp Nou crowd; and a top-secret game plan was hatched on the flight back to Spain after the first leg defeat. According to PSG, there is also a fourth decisive factor: the referee.

No one could sleep on the flight back to Barcelona from Paris. Luis Enrique was still quietly furious about the performance, and Sergio Busquets’ post-match interview, which pointed the finger of blame at Barça’s tactics, had done nothing to improve the mood.

Robert Moreno, then a member of Luis Enrique’s coaching staff and now coach of Sochi in Russia, watched the game again. When Barça landed in Spain again, he was clear about how they should approach the second leg.

They would abandon their 4-3-3 and play a 3-4-3 with left back Jordi Alba dropped and Rafinha Alcántara up front, allowing Lionel Messi a freer role.

There was a three-week gap before the second leg, so the new system could be practiced in the previous four league games. In the victories over Leganés, Atlético de Madrid, Sporting de Gijón and Celta de Vigo, variations of what the formation and starting eleven would be against PSG were implemented.

The less noise was made about the change to the 3-4-3, the better, and when club delegate Carles Naval handed out the scoresheets before the start of the matches, Barça were still, on paper, organized in a 4 -3-3.

When the big night arrived, there were Samuel Umtiti, Gerard Piqué and Javier Mascherano in a back three. Jordi Alba became an unused substitute: the beginning of a rift between him and his coach that took years to heal.

Training adjustments alone would never have been enough. Luis Enrique is a coach for whom the players would jump into the void if he asked them to. His leadership was key.

And there were also leaders in the field. Luis Suárez headed past Kevin Trapp after just three minutes, and when Layvin Kurzawa scored an own goal five minutes before half-time, the majority of the 96,290 spectators inside the Camp Nou chanted “Yes, we can.”

Barcelona now needed three more goals to win the tie, but Luis Enrique had always been convinced that PSG would score and that dictated his team talk at half-time, dedicated to preparing his players for when it happened.

In the 61st minute, after Lionel Messi scored a penalty to make it 3-0, Cavani made it 3-1 and 3-5 on aggregate. But Barcelona did not give up. ‘This was all a matter of belief. We never lost,” said the coach after the game.

Not even he expected that the scorer of the winning goal would be the youth player, youth player Sergi Roberto. After Neymar scored twice, Roberto completed the job in the 94th minute and 29 seconds.

“I saw him score a lot of goals when I was a kid, but I often joke with him that nowadays he can’t score under the rainbow,” Luis Enrique said after the match.

Barcelona president Josep Bartomeu recalled that his counterpart, Nasser Al-Khelaifi, declared the match won with five minutes left and left the box to go down to wait for his players at the mouth of the tunnel. ‘I do not like that. In that time we scored three goals,” Bartomeu said.

Al-Khelaifi was not the only one who changed positions in the stadium when the tie took a turn. The press box at the top of the main stand was full of television journalists who had to go down to pitch level with a couple of minutes left to take their places in the flash interview area.

When they started the trip they were 3-2 and Barcelona still needed two goals. They watched in disbelief in the bowels of the stadium through a small television screen as the last two entered. The cameras turned and some Barça fan journalists fell to the ground. Their French counterparts, who had previously been offended by the way journalists celebrated goals at home, looked on in disbelief.

The importance of those late Neymar goals did not go unnoticed by anyone after the game. And when all the newspapers the next day published the image of Lionel Messi raised up to his shoulders, the myth was born that Neymar decided at that moment that he had to leave the club to get out of Messi’s shadow.

It became an easy narrative to explain why Neymar would sign for PSG just four months later, although the reasons for that move were always more economic.

That image of Messi carried on the shoulders of Barça fans quickly became an Internet meme in France, when the Argentine was replaced by referee Aytekin.

Every 50-50 decision on the night had gone in Barcelona’s favor and PSG coach Emery later said: “We were eliminated because VAR didn’t exist yet.”

PSG sent a five-page complaint file to UEFA and, although there was never an official condemnation, Aytekin was never granted another Champions League knockout match.

What seemed like a penalty on Ángel di María de Mascherano was PSG’s biggest grievance. They were also angered by the penalty awarded to Suarez in stoppage time when he fell dramatically clutching his throat after contesting a cross with Marquinhos.

“There was a clear penalty against Di María that was not awarded,” Emery said. “And the Barcelona players, Suárez in particular, kept falling in the area, putting pressure on the referee, who in the end fell into the trap.”

It was later revealed that in PSG’s next league match, Emery had sought out French referee Tony Chapron after the match. “I thought he had come to question my refereeing, but he told me: “I have a question to ask you about the Barcelona game, can you explain the referee’s decisions to me?” I lied to him and told him that I had not seen the game.” Chapron said.

The game clearly haunted Emery until the end of the season, when he was fired. He also chased forward Cavani. He had a chance to put the result beyond doubt and recently told Relevo in a conversation about the importance of psychology in sport: ‘The first time I went (to see a therapist) was after Barça’s comeback against PSG.

‘It had a big impact on me. In five minutes everything had changed. Although it’s only football, it affects you and there were symptoms of anxiety, cold sweats, a feeling of dizziness when falling asleep. I went to the PSG doctor, whom I love very much, and he told me: “What is happening to you is happening to many people in different areas.” I realized he wasn’t a superhero.’

Barcelona’s superpowers didn’t last long either. Immediately after the match, their fans flocked to the city’s famous ‘La Rambla’ avenue, where they usually celebrate the Champions League victory. And in his press conference coach Luis Enrique said: “You can imagine what this means for our season.”

But far from being a catalyst for success, Barcelona lost 3-0 on aggregate to Juventus in the next round.

PSG can learn a lesson there: if they beat Barcelona tonight, they will still have to get through a semi-final before the final at Wembley. But first they need a comeback.

The Spanish word for this is ‘remontada’ and it marked the collective memory in France so much that it was accepted into the Larousse dictionary in 2021. It is now part of the lexicon; They just need it to also be part of their football history.