Porto, undeniably, have a massive mountain to climb when they travel to Anfield to face Liverpool on Tuesday night.
A horror show for the Portuguese side at the Dragao last month has meant that Porto are 5-0 down from the first leg, a result that they will have to better in order to progress to the quarter finals for the first time since 2015.
To put their task into contest, no team has ever come back from such a large first-leg deficit to win a two-legged tie. However, that particular record was broken last year when it looked as though Barcelona were down and out against Paris Saint-Germain.
Mission improbable for Porto at the home of the Premier League giants, and to do so they would have to equal at least equal an Anfield win record set by Sunderland back in 1930, but they will fight until the end and could to some other famous Champions League comebacks for inspiration.
Paris Saint-German 4-0 Barcelona
Barcelona 6-1 Paris Saint Germain (6-5 agg, Champions League, 2016/17)
4-0 down from the first leg in Paris, Barcelona were surely just playing for pride at Camp Nou in their last 16 second leg. They took a 3-0 lead before Edinson Canvani scored that all-important away goal, but as the minutes ticked away it looked as though Barca were heading out.
And then, with five minutes of normal time remaining, Barcelona sprung to life. Two goals from Neymar put the Spanish side on the cusp of the impossible and then, with virtually the last kick of the game, Sergi Roberto made himself a Barcelona legend by putting the home side 6-1 up, 6-5 on aggregate and the first time in Champions League history that a team had come back from such a huge first-leg deficit.
AC Milan 4-1 Deportivo La Coruna
Deportivo La Coruna 4-0 AC Milan (5-4 agg, Champions League 2003/04)
AC Milan, the defending champions, had made short work of Deportivo in the quarter final first leg at the San Siro and were fully expected to finish the job at the Riazor. However, a goal from Walter Pandiani put the cat among the pigeons and gave the Spanish side all the hope they needed to score twice more in the first half to lead 3-0 and, as it stood, go through on way goals.
Fran Gonzalez put the icing on the cake with fifteen minutes remaining, completed the miracle comeback, and ensured that Deportivo crashed out in the semi-finals (to Jose Mourinho’s Porto) rather than the last eight.
Real Madrid 4-2 Monaco
Monaco 3-1 Real Madrid (4-4 agg, Champions League 2003/04)
While one La Liga side was completing a storming comeback in Europe, another was crashing and burning in the same manner. Real Madrid. When Ronaldo put Real Madrid 4-1 up on Monaco with ten minutes remaining, it looked like job done for the 2002 champions’ progression the semi-finals. However, Fernando Morientes (on loan from Real) ensured that the French side had a glimmer of hope with a late effort to make it 4-2 on the night.
Morientes would end up playing a key role in his parent club’s downfall in the second leg. Down 1-0 on the night via Raul, Monaco scored three times without reply, Morientes again in between two Ludovic Giuly strikes, to complete the wildly unexpected comeback against the Galacticos.
Napoli 3-1 Chelsea
Chelsea 4-1 Napoli AET (5-4 agg, Champions League 2011/12)
In one of the most ridiculous seasons at Chelsea in recent memory (And that’s saying something), the season began with the appointment of Andre Villas-Boas, one of the brightest young managers in Europe at the time, and somehow ended with the Champions League trophy coming to Stamford Bridge against all the odds. The last 16 comeback against Napoli is probably the best microcosm for said season.
Down 3-1 from the first leg, Villas-Boas was sacked and replaced with Roberto Di Matteo before the return leg at Stamford Bridge. In one of his first matches in charge, Di Matteo oversaw a team performance free from the Villas-Boas reign, and that momentum alone seemed to power them past the Serie A side and on their way to the European title for the first time ever.