How did that happen? With two minutes of normal time remaining, Barcelona led PSG 3-1 but still needed THREE unanswered goals to reach the Champions League quarter-finals.
Two quickfire Neymar goals - the second a highly controversial penalty after an apparent Luis Suarez dive - levelled the tie at 5-5.
Then, in the fifth minute of stoppage time, Sergi Roberto struck to create a slice of Champions League history.
No side had ever turned around a four-goal first-leg deficit before, and that got us thinking about some other stunning comebacks - all now surpassed by Barca's mind-boggling heroics at Camp Nou.
Deportivo La Coruna 4-0 AC Milan (5-4 agg), 2004:
Deportivo were among Spain's major forces just after the turn of the century and one of their finest moments in Europe came in April 2004 when, despite being 4-1 down from the first leg of their Champions League quarter-final with AC Milan, they stunned the Italians at home.
Walter Pandiani, Juan Carlos Valeron and Albert Luque had Depor ahead on away goals before half-time, with Fran Gonzalez - who played for them in the second division in the late 80s and is still their record appearance holder - fittingly scored the fourth to make sure of their passage.
Depor were eliminated by eventual winners Porto in the semi-finals, but this comeback stood as arguably the very best in Champions League history - until now.
Liverpool 3-3 AC Milan (AET, 3-2 on pens), 2005
That famous night in Istanbul. Liverpool found themselves on the end of a hiding at half-time in the 2005 Champions League final, as Paolo Maldini and a Hernan Crespo brace had the Serie A side 3-0 up.
But the second half proved to be one of the most iconic 45 minutes in Liverpool's history, with goals from Steven Gerrard, Vladimir Smicer and Xabi Alonso levelling the match up by the hour mark.
Milan then failed to hold their nerve in the penalty shootout, as Jerzy Dudek's leggy antics in the Liverpool goal helped the Pole outsmart both Andrea Pirlo and Andriy Shevchenko after Serginho blazed the first kick over, resulting in the Premier League side lifting their fifth European title.
Manchester United 2-1 Bayern Munich, 1999
Possibly the two most dramatic minutes in the history of European club football.
Manchester United were trailing 1-0 to Bayern Munich in the 1999 final at Camp Nou, with Mario Basler's skidding free-kick into the bottom-right corner looking set to be enough for the Bavarian giants to end a 23-year wait for glory in the continent's top-tier competition.
However, the United of Alex Ferguson's era could never be discounted until the final whistle, and substitute Teddy Sheringham swept Ryan Giggs' shot into the bottom corner to bring the scores level in the 91st minute.
Ole Gunnar Solskjaer, another late substitute, avoided the need for extra time, stabbing Sheringham's header from a David Beckham corner into the roof of the net as United completed an historic treble in astonishing fashion.
Monaco 3-1 Real Madrid (5-5 agg, Monaco won on away goals), 2004
Monaco were an unexpected member of the last eight in the 2003-04 Champions League and had seemingly been put in their place after losing 4-2 at Real Madrid in the first leg, even if Fernando Morientes - on loan from the Spanish giants - netted their second late on to give them a chance.
A Raul goal nine minutes before the break in the return leg in Monte Carlo made their task even tougher, but Monaco rallied admirably - Ludovic Giuly pulled one back on the stroke of half-time, with Morientes then adding a second just after the restart.
Giuly - whose performances with Monaco ultimately earned him a move to Madrid's bitter rivals Barca - grabbed the decisive goal midway through the second half to secure progression, with Didier Deschamps' side finally halted by Porto in the final.
Barcelona 5-1 Chelsea (AET, 6-4 agg), 2000
It seems fitting to end this run-down with another famous Barca turnaround.
A 3-1 first-leg loss at Stamford Bridge - having trailed 3-0 - had Barca in danger of being on the wrong end of a major 1999-00 Champions League upset prior to the Roman Abramovich era, but in the return match the Catalans showed their true class.
Tore Andre Flo's 60th-minute goal was sending Chelsea through despite Rivaldo and Luis Figo scoring before the break, but Dani Garcia scored seven minutes from the end of regulation to force extra-time.
Rivaldo then converted a penalty after Celestine Babayaro was sent off and Patrick Kluivert wrapped things up, crushing Chelsea's dreams.
