The Biggest Shocks in the History of the Champions League Round of 16

When Paris Saint-Germain absolutely demolished Barcelona 4-0 at the Parc des Princes, it was thought that the tie was over as Barcelona didn’t look at all threatening in the game and were trounced by a sensational PSG side with former Real Madrid man, Angel Di Maria, running the show.

However, the second leg started as if Barcelona were on a mission to stop all doubt, with Luis Suarez scoring after three minutes to give them the perfect start, before they took a 2-0 lead into half time. People thought the tie was over, however, when Edinson Cavani netted an away goal which meant Barcelona had to score six to advance (four more at the time), and that all but seemed impossible for any club, never mind one that contained Lionel Messi, Suarez, and Neymar

They pull another back though, and two minutes to go in normal time, Barcelona still needed to score three goals and fans were leaving the ground still as the pure mathematics of the equation itself seemed near impossible.

Two goals in the next five minutes brought the eyes of the world upon the Nou Camp as the most dramatic European knockout tie in history was taking place, and a goal in the 95th minute from Sergi Roberto sent Barcelona would end up sealing the deal.

Probably the greatest game in round of 16 history.

Fast forward two years, however, and times were different for PSG.

With and 10 first team players unavailable, and a 2-0 deficit with away goals, Manchester United were huge underdogs going into this game at the Parc des Princes with PSG already looking ahead to the quarter-finals.

Despite a much weaker team, United started the game very strong, with Romelu Lukaku scoring after two minutes, and despite PSG levelling the score, Lukaku got a second away goal to cancel out PSG’s from the first leg in a fantastic attacking display from Ole Gunnar Solskjaer's men.

The whole second half had both sets of fans on edge, knowing how much the next goal meant, but with the game dwindling down, it looked as if PSG were going to survive the scare, but United were awarded a penalty in a stunning VAR call on Pascal Kimpembe only for Marcus Rashford to score deep into stoppage time.

Off the back of winning three straight Champions League titles and winning the first leg 2-1 in Amsterdam, it looked as if the second leg was a formality for Real Madrid, but Ajax had different ideas.

Two goals in the first 20 minutes showed that they were there to cause the upset, and adding a third after an hour showcased their quality with them dominating the reigning champions in their own stadium.

After scoring a goal in the 70th minute, there was still a chance Real could use their experience to come back, but a goal just two minutes later by Ajax shut that down and the Dutch giants racked up one of their greatest ever Champions League victories.

Even after winning the first leg in Portugal, Porto was still counted out in this tie, with Sir Alex Ferguson's Manchester United the massive favourites over Jose Mourinho’s Porto.

Paul Scholes scored after half an hour and looked to send United through to the next round on away goals, with them keeping the lead right up until the end of the game.

Porto’s Francisco Costinha benefited from a mistake from Tim Howard, where he just had to tap the ball in from a few yards out, to send underdogs Porto into the next round and Jose Mourinho down the Old Trafford sideline. It started "The Special One's" era and a period of three years without a Premier League for United as Mourinho would go on to win the Champions League with Porto and then take over England with Chelsea next season.

Arsenal were huge underdogs going into the game at the Emirates with Barcelona the heavy favourites for the title itself with one of the best squads ever assembled, whereas Arsenal had an 18-year-old Jack Wilshere in midfield that was relatively unknown compared to the famous midfield in front of him: Sergio Busquets, Xaxi, and Andreas Iniesta.

Barcelona took the lead in the 26th minute through David Villa and it felt like they were going to eventually add more goals, but Jack Wilshere had the performance of a lifetime which saw the game shift the other way.

Wilshere held his own against that unrivalled modern day midfield trio of Busquets, Xaxi and Iniesta, and led Arsenal to score two late goals in the game to complete a stunning comeback where Andrei Arshavin netted a famous winner.

Wilshere's display remains probably the best performance by an English teenager in the Champions League since Wayne Rooney's debut against Fenerbahce.