PSG Humiliated Before Season-Defining Champions League and Ligue 1 Fixtures

"It is the night we've imagined in our dreams." 

That is how Montpellier midfielder Morgan Sanson described his team's 3-0 victory over Paris Saint-Germain (via L'Equipe). 

For the champions, it was a nightmare. 

Layvin Kurzawa and Angel Di Maria returned to the lineup, seemingly giving Paris a significant advantage. 

The presence of Kurzawa at left-back allowed Unai Emery to deploy his preferred strategy of using hyper-aggressive full-backs to provide width. 

Montpellier manager Frederic Hantz predicted this strategy and instructed his team to play passes into the gaps left by the advancing full-backs early and often.

It was an ambush on the Mediterranean. 

After just 36 seconds, Montpellier played their first long ball. It wasn't an aimless punt but a clearly designed ploy to try to catch Paris' backline on the turn. 

From most goal kicks, they they had six players in the opposition half, overloading the attacking zone. 

It was a risky strategy for the hosts but proved effective at creating numerical overloads in dangerous positions. 

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As soon as Montpellier won the ball, they looked for an opportunity to go vertical, and time and again, they found themselves in advantageous situations.  

Christopher Nkunku, making his first start of the season, had a fine header well-saved inside the first 10 minutes.

Had he scored, Paris might have avoided this catastrophe, but they were already looking ragged and Montpellier were gaining in confidence. 

Emery had selected a team of dribblers. Lucas Moura, Serge Aurier, Blaise Matuidi, Di Maria, Kurzawa and Nkunku all love running with the ball at their feet. 

Where more thoughtful ball movement might have punctured Montpellier's aggressive pressing, PSG's individual approach played right into their strategy. 

Over and again, packs of Montpellier players swarmed isolated Paris runners and swiftly played the ball into attacking zones.

The champions did not heed their warning when Paul Lasne was, rightly, denied an opening goal by the assistant referee's flag. 

Instead, as the first half wore on, Paris were dragged into Montpellier's chaotic approach. 

In the absence of Marco Verratti and Thiago Motta, they lacked an organising midfielder capable of exploiting that space. 

Nkunku and Grzegorz Krychowiak were left to try to thread unlikely passes as the attacking line pulled wide and deep in an attempt to stretch the home side's defence.

Di Maria tried dropping into the space to direct play, but he was imprecise and wasteful. 

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Montpellier deservedly took the lead on the stroke of half-time, again via a long pass forward. 

With Marquinhos too busy grappling with opposition forward Steve Mounie, teammate Paul-Bastien Lasne was able to arrive unmarked and lift his finish over the helpless Alphonse Areola. 

Again, it was a premeditated move and not a hopeful punt. 

Montpellier lined up two wide men and two forwards man-for-man with Paris' backline. This meant that only one player had to beat his man for pace in order to create a numerical overload. 

It is a simple tactic aimed at producing confusion in the opposition defence, and that is precisely what it achieved. 

Montpellier's second goal, minutes into the second half, was a similar story.

A long ball headed on into the space left by Serge Aurier pushing up the pitch allowed Morgan Sanson to beat Thiago Silva to the loose ball and set up Ellyes Skhiri's sensational first-time shot. 

While the finish was exceptional, it was the intelligence and effort of the build-up that exposed PSG again. 

Paris' mindless defending saw seven of their outfield players charging towards Sanson with none of them picking up Skhiri's late arrival at the top of the box. 

Had Lucas not been harshly flagged offside when clean through alongside Cavani in the 57th-minute, Paris would surely have made it 2-1 and perhaps mounted a comeback. 

Although their performance up to that point suggests otherwise. 

The immediate impact of Hatem Ben Arfa's introduction at the expense of Nkunku suggests that Emery erred in leaving the dynamic playmaker out of the starting lineup. 

Paris had lacked direction but Ben Arfa immediately took control, directing the movement of his teammates and orchestrating attacks. 

He made more chances in the final half-hour than his teammates managed in the entire game. 

Just as Paris were finally finding a foothold, Ryad Boudebouz wrapped up the stunning win after a sensational individual counter-attack with 10 minutes to play. 

It was the third shot on target and the third goal for the home side, and Areola will feel disappointed at having failed to get near Boudebouz's looping effort. 

This was a disastrous result, and the timing could not have been worse. 

Paris face their final Champions League group stage game when Ludogorets visit the Parc des Princes on Tuesday. 

That is a must-win fixture with Arsenal level on points. Any slip against the Bulgarians will provide an opportunity for the Gunners to seize top spot and the advantages that entails. 

Then on Sunday, the champions host Nice in a match that has assumed greater importance in the wake of this reverse. 

Les Aiglons could return to the top of Ligue 1 when they host Toulouse on Sunday and extend their lead over Paris in the process. 

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The players' mentality will have been significantly underwhelmed by their humiliation at the hands of Montpellier. Emery admitted as much in the aftermath, saying, "We have lost a little of our confidence." (via Marc Alvarez of Canal-Supporters.com)

That is a significant understatement. 

This was not just Montpellier's biggest win of the season but their biggest since a 4-1 win over the remarkably-poor Troyes in April.

In the entirety of last season, PSG lost twice in the league. 

They have now lost three times in this campaign, as many defeats as sustained in all of the 2013-14 and 2014-15 seasons. 

Not since the final months of the doomed Antoine Kombouare regime have PSG been beaten by a three-goal margin. 

After months of gradual progress, Emery's side have slid right back down into the abyss. 

Speaking in September, Montpellier's Boudebouz told Canal that Paris are a target this season. In the absence of Zlatan Ibrahimovic, he labelled them "fragile and less impressive."

Now, with potentially-decisive Ligue 1 and Champions League fixtures in the coming week, his words are proving prophetic.