Barcelona v PSG: Five things we learned as Neymar steals the show in historic Champions League comeback

Neymar rises to the occasion, PSG realise that they have an awful lot more work to do before they can count themselves as one of Europe's big teams and Barcelona happy to play dirty

Barcelona completed one of the most sensational comebacks in the history of football by beating Paris Saint-Germain 6-1 to reach the Champions League quarterfinals on Wednesday, scoring the decisive goal of a 6-5 victory on aggregate in the fifth minute of stoppage time.

Sergi Roberto's dramatic late goal sent the Nou Camp into hysteria and made Barcelona the first team ever to overturn a 4-0 first-leg defeat since the Champions League format started in the 1992-93 season.

PSG seemed certain to go through after Edinson Cavani scored a valuable away goal following Barcelona's opening salvo of three goals. But Barcelona rallied and left the French champions stunned.

Here are five things we learned...

Neymar rises to the occasion

Neymar stepped up to the plate in emphatic fashion (Getty)

All the pre-match build-up had focused on Messi and what the Argentine wizard would bring to the game but, on the big occasion, it was his fellow South American who stepped up to the plate and delivered.

His energy was infectious and his composure on the ball gave little indication that that this was an all-or-nothing showdown in the last-16 of the Champions League.

His stunning free-kick was what kick-started Barcelona's late, late fightback before his penalty kick three minutes later put the home side in reaching distance of the impossible. And then, in a moment of sheer class, he floated in an exquisite delivery to set Sergi Roberto up for the winner. An inspired evening from the Brazilian.

Progress? What progress?

PSG started the match incredibly tentatively (Getty)

For all of their riches and for all of their domestic glory, continental success had long eluded Les Rouge-et-Bleu, one solitary UEFA Cup Winners' Cup aside. But after that swaggering 4-0 victory in Paris, the consensus was that PSG had finally come of age in European competition.

And then all of that hard work was undone in one single, unforgettable night in Barcelona. PSG started tentatively, conceding within the first 120 seconds, and things only got worse from thereon in for the French champions.

They made giant strides forward in Paris but, rather perversely, this season marks the first time they have failed to reach the quarter-finals of the Champions League in four years.

Worse, the mental scars from this performance will last long after the season has finished. With Monaco and Nice also battling hard in Ligue 1, there are an awful lot of pieces for Unai Emery to pick up, in very little time.

Barcelona prepared to play dirty

Rarely has an average position graph caused quite so much amusement on Twitter. Because at half-time, the stats showed that Barcelona had played the entire first 45 minutes with their defence spending more time in PSG's half than their own.

It was a high-risk strategy that paid off. PSG only needed to score one goal to seemingly kill the tie, which Cavani duly grabbed in the second-half. But still Barcelona pressed on, in the ultimate backs-against-the-wall, attacking performance.

Their first two goals — opportunistic, scrappy, physical — exemplified their approach as they abandoned their free-flowing principals and went for the jugular. And it was fitting that the move that led to their winning goal was initiated by a rampaging Marc-Andre ter Stegen winning the ball in PSG's other.

Luis Enrique abandoned his principals in favour of pragmatism against PSG: one of the most famous victories in the history of the club was his reward.

A tale of two goalkeepers

The two goalkeepers had very different evenings (Getty)

Appropriately for this crazy, crazy match, both goalkeepers played a part in Sergi Roberto's scarcely believable winning goal.

With less than a minute left to play and Barcelona still remaining one goal, Ter Stegen hared down the pitch to join the attack and, while recycling possession for one last, long punt down-field, he was hacked down by Veratti. The referee awarded a free-kick, the ball was swung into the box and Sergi Roberto volley over Kevin Trapp and the rest, already, is history.

PSG's defence completely fell to pieces at the Nou Camp, but Trapp particularly struggled and looks a long way short of the required standard.

In the summer, PSG allowed Salvatore Sirigu on loan to Seville. Trapp has done little to prove he is a more adept keeper and that decision now looks especially rash.

Cavani delivers his end of the bargain

Cavani saved the day for PSG (Getty)

What a shame an in-form Edinson Cavani will not grace the latter stages of this tournament.

That's not to suggest the Uruguayan was infallible against Barcelona. In fact, he ended up missing a number of presentable opportunities, seeing one shot well saved by Marc-Andre ter Stegen and hitting the post at the start of the second-half.

But that is Cavani's way. His conversion rate may be middling but in this form he seems to guarantee a goal: his effort against Barcelona making him PSG's joint-highest scorer in the Champions League alongside Zlatan Ibrahimovic.

On a night that PSG's defence fell to pieces, Cavani made good on his end of the bargain. He can consider himself unfortunate to be on the losing team.