Tonight and tomorrow, Premier League clubs Arsenal and Manchester City will have to overturn 2-0 first-leg deficits if they are to continue in this season's Champions League.
Although the duo, who face Bayern Munich and Barcelona respectively, are big underdogs to advance through to the quarter-finals, it is a scoreline that has been overturned in years gone by.
Below, Sports Mole picks out five of the most memorable comebacks in Champions League history to act as inspiration for the English teams.
1. Barcelona 5-1 Chelsea (6-4 agg), 2000
Although Chelsea were by no means the force that they are now, 14 years ago they took a 3-1 lead to the Camp Nou, which many expected them to defend. Although they conceded twice, when Tore Andre Flo scored in the closing stages, it appeared that the West Londoners were bound for the semi-finals. However, Dani Garcia responded to force extra time, before Rivaldo and Patrick Kluivert sealed a comprehensive victory for the home team.
2. Deportivo La Coruna 4-0 AC Milan (5-4 agg), 2004
Walter Pandiani opened the scoring during the opening leg at the San Siro, but after a Kaka-inspired Milan fired in four goals, his strike appeared to be a mere consolation. Not so, as it proved, because Pandiani, Juan Carlos Valeron and Alberto Luque sent Depor into a 3-0 lead at the Estadio Riazor, before substitute Fran Gonzalez added a fourth goal 14 minutes from time to ensure his side's passage through to the semi-finals.
3. Monaco 3-1 Real Madrid (5-5 agg), 2004
Whoever sanctioned the loan deal that saw Fernando Morientes leave Madrid for Monaco at the start of the 2003-04 season will not have been looked upon favourably come the end of this quarter-final. No block was put in place to prevent him playing against his parent club and he duly found the net during the first match in the Bernabeu, which ended in a 4-2 defeat for Monaco. When Raul put Real 1-0 up at the Stade Louis II, it seemed that the Spaniards would cruise through to the semi-finals, only for a brace from Ludovic Giuly and another strike from Morientes to send Los Blancos out on the away goals rule.
4. Bayern Munich 2-3 Inter Milan (3-3 agg), 2011
Only one team had previously managed to recover from a first-leg home deficit prior to Inter's triumph in the San Siro. Bayern won 1-0 in Italy and although Samuel Eto'o levelled up the score during the second meeting, goals from Mario Gomez and Thomas Muller put the hosts in the ascendancy. Holders Inter refused to be defeated, though, as they booked their place in the last eight thanks to goals from Wesley Sneijder and Goran Pandev.
5. Chelsea 4-1 Napoli (5-4 agg), 2012
The 3-1 loss in Naples proved to be Andre Villas-Boas's last European match in charge of Chelsea, with his assistant Roberto Di Matteo appointed on an interim basis for the return leg. Although little was expected, the Blues responded positively at Stamford Bridge, with Didier Drogba and John Terry putting them 2-0 up. Gokhan Inler then struck as Napoli went back in front on aggregate, but Frank Lampard forced extra time from the penalty spot. As penalties loomed, Branislav Ivanovic fired in the winning goal for the hosts, who went on to win the trophy.
