Liverpool completed an unbelievable comeback from 3-0 down after the first leg to beat Barcelona 4-0 and reach the Champions League final.
It was a night of incredible drama at Anfield - and it means Barcelona have now surrendered three-goal leads in the knockout stages in each of the past two seasons.
Indeed some of the biggest moments in Champions League history involve teams fighting back from several goals down to defy the odds.
And - Manchester United fans - we haven't included that night because this is about overturning big deficits!
2018-19 SF: Liverpool stun Barca in famous Anfield night
Aggregate 4-3: Barcelona 3-0 Liverpool/Liverpool 4-0 Barcelona
A late Lionel Messi masterclass at the Nou Camp left Liverpool's hopes of a second successive Champions League final dangling by a thread. The Argentine scored twice, including a sensational free-kick - his 600th Barcelona goal.
Even the most optimistic Liverpool fan could not have held out much hope after star forwards Mohamed Salah and Roberto Firmino were ruled out of the second leg through injury.
Divock Origi gave them hope in the seventh minute but they could not find a second goal before the break.
A turning point saw pantomime villain Luis Suarez injure Andy Robertson, leaving the Scot to be replaced by Georginio Wijnaldum. And his two goals in 122 seconds levelled the tie.
Origi scored a winner which will live long in the memory, turning home Trent Alexander-Arnold's corner while Barcelona switched off. Cue scenes of pandemonium at the final whistle.
2017-18 QF: Barcelona stunned in thrilling Roma fightback
Aggregate 4-4: Barcelona 4-1 Roma/Roma 3-0 Barcelona - Roma win on away goals
Roma reached the semi-finals of Europe's premier competition for the first since since 1984
Sound familiar? Barcelona looked to have this quarter-final tie sewn up in the first leg at the Nou Camp after Gerard Pique and Luis Suarez added to own goals from Daniele de Rossi and Kostas Manolas.
But what looked like a consolation in the 80th minute from former Manchester City striker Edin Dzeko proved to be crucial.
The Bosnian put Roma ahead after just six minutes in the return leg before a De Rossi penalty and a Manolas header atoned for their Nou Camp mistakes and led the Italian side to an unfathomable win on away goals. Cue madness in the Stadio Olympico stands.
After the match, Dzeko said: "Nobody believed in us before the game - they gave us a 5% chance of winning. The win is difficult to describe. We will enjoy the semi-finals - I do not fear anyone."
The dream didn't last much longer for Roma, as they were beaten 5-2 at Anfield by Liverpool and 7-6 on aggregate.
2004-05 final: That night in Istanbul
AC Milan 3-3 Liverpool - Liverpool win 3-2 on penalties
Liverpool players celebrate with the trophy after winning the 2004-05 Champions League final on penalties against AC Milan in Istanbul
While all the other entries on this list happened over two legs, the Reds squeezed their comeback into 45 second-half minutes (plus extra time and penalties) in the 2005 final.
A rollercoaster of emotion from start to finish, this was one of the gutsiest comebacks in the history of the Champions League. What was meant to be Liverpool's big moment quickly fell to pieces, with Milan captain Paolo Maldini grabbing a first-minute lead before Hernan Crespo scored twice to put Milan 3-0 up.
The game looked over at half-time but six mad second-half minutes saw captain and talisman Steven Gerrard, Vladimir Smicer and Xabi Alonso score to level the tie and take it to penalties. Liverpool won the shootout with goalkeeper Jerzy Dudek the hero and Gerrard declaring his love of the club soon after, having been heavily linked with a move to Chelsea.
"How can I think of leaving Liverpool on a night like this?" he said, before taking the trophy to bed with him.
2011-12 last 16: Would-be champions Chelsea refuse to go out
Aggregate 5-4: Napoli 3-1 Chelsea/Chelsea 4-1 Napoli AET
Chelsea overturned a three-goal first-leg deficit against Napoli en route to winning their only Champions League
Two goals from Napoli's Ezequiel Lavezzi either side of an Edinson Cavani header cancelled out Juan Mata's early volley in a scintillating performance at the San Paulo Stadium that put the Italians firmly on course for the quarter-finals.
Two weeks later Roberto di Matteo had replaced Andre Villas-Boas as Chelsea's caretaker manager in a desperate attempt to galvanise the players and rescue the season.
It had the desired effect as Didier Drogba, John Terry and Frank Lampard all scored to take the tie to extra time at Stamford Bridge.
After Branislav Ivanovic's dramatic winner sent Chelsea through, Di Matteo said: "I've had some great nights but I think this will go down in the club's history."
He was right, as his Blues went on to win their first and only Champions League title - beating Bayern Munich on penalties at their own stadium.
2003-04 QF: Champions Milan crumble in Spain
Aggregate 5-4: AC Milan 4-1 Deportivo La Coruna/Deportivo 4-0 AC Milan
AC Milan playmaker Kaka lies on the grass in the 4-0 quarter-final defeat by Deportivo la Coruna in the 2003-04 Champions League
"Miracles often happen, things you might not rationally expect," Deportivo coach Javier Irureta said after his side were hammered 4-1 by reigning champions AC Milan in the first leg of their 2003-04 quarter-final.
His words were prophetic as a Milan side containing Maldini, Alessandro Nesta, Cafu, Clarence Seedorf, Andrea Pirlo, Kaka and Andriy Shevchenko were stunned in the second leg.
Deportivo produced a crushing display with goals from Walter Pandiani, Juan Valeron, Albert Luque and Gonzalo Fran sending the home fans into a frenzy.
A single goal from a Porto side managed by a young Jose Mourinho - who would go on to win the competition - deprived them of a place in the final.
1999-00 QF: Extra-time goals send Chelsea out in Barcelona
Aggregate 6-4: Chelsea 3-1 Barcelona/Barcelona 5-1 Chelsea
Patrick Kluivert of Barcelona celebrates scoring the winner to eliminate Chelsea in the quarter-finals of the 1999-2000 Champions League at the Nou Camp
Chelsea fans were dreaming after eight glorious first-half minutes saw a trademark Gianfranco Zola free-kick and a Tore Andre Flo double give them a stunning 3-0 first-leg lead at Stamford Bridge and put a semi-final place in sight, before Luis Figo struck to give Barcelona the away goal they needed to take back to the Nou Camp.
Extra-time goals from Rivaldo and Patrick Kluivert in the second leg denied Chelsea a memorable victory. Barca would go on to lose to Valencia in the semis.
2016-17 last 16: Barcelona defy belief to shatter PSG
Aggregate 6-5: Paris St-Germain 4-0 Barcelona/Barcelona 6-1 Paris St-Germain
Sergi Roberto celebrates Barcelona's sixth goal of the night to knock PSG out of the 2016-17 Champions League
The only time any side has overturned a four-goal aggregate lead.
Strikes from Angel di Maria (two), Julian Draxler and Edinson Cavani left Barcelona needing a miracle against Paris St-Germain to reach the quarter-finals.
What followed was nothing short of extraordinary.
Barcelona knew they had to go for it in the return leg and gave themselves a chance with three goals in the first 50 minutes at the Nou Camp. Cavani then struck for PSG to seemingly end the tie and leave their opponents needing three more goals to advance.
In the most incredible finale, Neymar scored in the 88th and 91st minute against his future employers before Sergi Roberto's 95th-minute winner completed a turnaround that had to be seen to be believed.
"Utter mayhem" and "deep, instinctive passion at its most authentic and unrefined" were seen by BBC Sport's Spanish football writer Andy West after the full-time whistle.
2018-19 last 16: Late VAR drama makes history in Paris
Aggregate 3-3: Man Utd 0-2 PSG/PSG 1-3 Man Utd - Man Utd win on away goals
Manchester United's Marcus Rashford scores a controversial penalty after VAR intervention to knock PSG out of this season's Champions League
A late penalty. VAR. A Neymar rant. This game had it all.
Manchester United were flying with 10 wins in 11 games after Ole Gunnar Solskjaer had taken over as caretaker manager following the dismissal of Jose Mourinho and welcomed PSG with renewed optimism.
But they were outclassed by the French side at Old Trafford, with second-half goals from Presnel Kimpembe and Kylian Mbappe leaving them with the task of overturning a two-goal deficit away from home - a feat never achieved before. They would also need to do it without Paul Pogba, who had been sent off for two yellow cards.
Deep into injury time in the second leg, United led 2-1 on the night, following first-half goals from Romelu Lukaku (two) and PSG's Juan Bernat, but the hosts were set for a 3-2 aggregate win and a place in the quarter-finals. Then Diogo Dalot's shot deflected behind off Presnel Kimpembe for a corner.
Or so we thought.
After looking again at the incident using VAR, Slovenian referee Damir Skomina decided it had struck Kimpembe's arm and awarded United a controversial penalty to the astonishment of the home crowd. Marcus Rashford stepped up to drill the ball home and send his team through, shattering PSG's Champions League dream once again.
Neymar, who missed the game through injury, could not contain his anger at the decision. In a social media rage, he said: "It's a disgrace. Four guys who know nothing about football watch a slow-motion replay in front of the television."