Chelsea will need to draw on the inspiration and belief from two of their fiercest rivals to overcome a three-goal deficit against Bayern Munich in the Champions League.
Frank Lampard's side go into Saturday's second leg trailing by three goals and will need to stage a remarkable turnaround to reach the quarter-finals.
But they will not need to look far back in the history books to see that all might not be lost. Last season's final in Madrid, where Liverpool beat Tottenham 2-0 in an all-English final, was set up by two of the most incredible turnarounds in recent memory.
The Reds fought back from a 3-0 first-leg deficit to defeat tournament favourites Barcelona on an incredible night of drama at Anfield in May 2019.
And a day later, Lucas Moura completed his hat-trick in the sixth minute of stoppage time as Spurs fought from 2-0 down on the night and 3-0 on aggregate to overcome Ajax on their own patch.
Indeed some of the biggest moments in Champions League history involve teams fighting back from several goals down to defy the odds.
Here we look back at some of those occasions when victory was snatched from the jaws of defeat, and you can rank them in order of what you think is the greatest comeback.
Oh, and Manchester United fans, we haven't included "that" night because this is about overturning big deficits!
A version of this feature was published in May 2019.
2018-19 semi-final: Moura hat-trick as Tottenham produce Houdini act
Aggregate 3-3: Tottenham 0-1 Ajax/Ajax 2-3 Tottenham - Tottenham win on away goals
No wonder Mauricio Pochettino was left in tears at the end of the match. The Argentine manager had just masterminded arguably his side's greatest performance during his tenure - and that coming after the remarkable quarter-final success over Manchester City.
The London club were 1-0 down after the first leg which became 3-0 on aggregate after 35 minutes inside the Amsterdam Arena. But then the game took on a different complexion in four remarkable minutes shortly after the restart, courtesy of Moura's double.
Spurs continued to search for that all-important third but it looked like it was never coming with keeper Andre Onana keeping the visiting attack at bay. But with time running out, the man of the night used all his remaining energy to send a low shot past the reach of the Cameroon international.
2018-19 semi-final: 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.
Divock Origi gave them hope in the seventh minute of the second leg but they could not find a second goal before the break. Georginio Wijnaldum's two goals in 122 seconds then levelled the tie, before Origi scored the winner - turning home Trent Alexander-Arnold's corner while Barcelona switched off.
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 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.
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.
2017-18 quarter-final: Barcelona stunned in thrilling Roma fightback
Aggregate 4-4: Barcelona 4-1 Roma/Roma 3-0 Barcelona - Roma win on away goals
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.
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
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 near 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.
2011-12 last 16: Would-be champions Chelsea refuse to go out
Aggregate 5-4: Napoli 3-1 Chelsea/Chelsea 4-1 Napoli (AET)
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, before Branislav Ivanovic's dramatic winner sent Chelsea through.
2004-05 final: That night in Istanbul
AC Milan 3-3 Liverpool (AET) - Liverpool win 3-2 on penalties
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.
2003-04 quarter-final: Champions Milan crumble in Spain
Aggregate 5-4: AC Milan 4-1 Deportivo La Coruna/Deportivo 4-0 AC Milan
"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.
1999-2000 quarter-final: Extra-time goals send Chelsea out in Barcelona
Aggregate 6-4: Chelsea 3-1 Barcelona/Barcelona 5-1 Chelsea (AET)
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.
Rank these UCL comebacks
How do you rank these Champions League comebacks
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