Man City defeated PSG 1-0 in the second leg (3-2 in aggregate) and reached the semi-final stage of the UEFA Champions League for the first time in their history. It was a monumental achievement, and one they achieved with a compactness in defence which has deserted them for most of this season.

They were, in no small way, helped by PSG's tactical mistakes on the night, along with injuries and suspensions. By the time the night ended, all of the three first choice midfielders of the French club were missing from the pitch, and Man City took full advantage of it.

How they lined up

With the league title out of reach, Manuel Pellegrini opted to leave out Bacary Sagna, Gael Clichy, Fernandinho, Kevin de Bruyne and David Silva out of the starting lineup during their clash against West Brom at the weekend. These players returned to the lineup against PSG with Pellegrini shifting back to his 4-2-3-1, after opting for a 4-4-2 against the Baggies.

PSG XI (3-5-2): Kevin Trapp(GK); Serge Aurier, Thiago Silva, Marquinhos; Gregory Van der Wiel, Adrien Rabiot, Thiago Motta, Angel Di Maria, Maxwell; Zlatan Ibrahimovic, Edinson Cavani

Laurent Blanc, on the other hand, rested eight of his players during the 0-2 win against Guingamp. The Frenchman reinstated the stars for this game against Man City, although he was missing a few through injuries and suspension. Both Blaise Matuidi and David Luiz missed the second leg after picking up a yellow card each in the first. With Marco Verratti also missing the game due to an injury, Blanc made a tactical change for this game. He switched to a 3-5-2 formation, with Aurier, Thiago Silva and Marquinhos forming the back-three.

PSG dominated possession but not the match

Not many teams come to the Etihad and dominate 62.9% of the possession in match . However, like the first leg, City sat back and played on the counter-attack, allowing PSG to take control of the ball. Although Pellegrini started with a 4-2-3-1 formation, while defending they reorganized themselves into 4-4-2 with two banks of four defending their goal. De Bruyne joined Aguero upfront , while David Silva and Jesus Navas dropped down to the wings to protect the fullbacks.

With City outnumbering PSG on the wings, the French club lost two attacking outlets in the game, while the likes of Di Maria and Rabiot failed to carve out openings through the middle. Moreover, with Matuidi, who proved to be a big threat in attack in the first leg with his forward runs from midfield, missing the game, PSG didn't have enough impetus at the center of the park to rattle the Man City midfielders. This led to very slow build-up plays from PSG, and they hardly tested Hart on the night – apart from a couple of free-kicks by Zlatan.

Aurier's night of misery

Serge Aurier is a lot of things – athletic, pacy, outspoken – but he is not a center back. The 23-year-old fullback was asked to play on the right side of a three-man defence by Blanc, and he had a night to forget. Playing out of his natural position, the Ivorian made a host of mistakes, and he was lucky that City were not clinical enough to punish him for those in the first half.

He gave the ball away constantly and two of them turned into goal-scoring opportunities for City. In the 28th minute, Aurier turned over the possession at the back, and Sergio Aguero won a penalty. The Argentine, like Zlatan in the first leg, failed to convert from the spot and PSG were let off the hook. Few minutes later, he misplaced a pass to Navas at the edge of the PSG box, and the winger came dangerously close to scoring.

Defensively he was caught out of position time and again, with Aguero and Silva looking to exploit his presence in the back-three.

Motta's injury and more PSG players playing out of position

Thiago Motta limped off in the 44th minute holding his hamstring and Blanc was forced to make a tactical change. Lucas Moura came on for the Italian international, and PSG switched to a more conventional 4-4-2. Moura, who scored a couple of goals at the weekend, shifted to the right wing, while Di Maria moved out wide to the left.

However, with a central midfielder short on the pitch, Blanc moved Marquinhos out of the defence and placed him alongside Rabiot in the midfield. This is possibly the worst midfield combination PSG can come up with, with a fully-fit squad. To make matters worse, Aurier was now partnering Thiago Silva at the center of the four-man defence.

Although Blanc's option was limited, but when you are forced to compromise in a match, it is better to do so in the wide areas, rather than in the middle. A team can survive with weak wingers or fullbacks, but not with a weak central midfield and central defensive pairing.

Eventually, in the 61st minute Blanc brought on Javier Pastore in place of Aurier and pushed Marquinhos back to the defence. However, the Argentine did not have the kind of impact he was hoping for, as the attacking midfielder was restrained from having to play in alongside a central midfielder, instead of playing ahead of them.

De Bruyne exploits the space which was left vacant by Motta

Motta is not only the most experienced PSG midfielder, but he is also their most important one defensively. The Italian shields the defence, and allows his partners to move forward and join the attack. Unsurprisingly, when Man City's goal arrived in the 75th minute, it arrived from the space vacated by Motta's departure. As the ball reached De Bruyne at the edge of the box, Cavani was the one trying to close him down, but his defensive skills were no match for the former Chelsea man, as he drifted past him with a drop of a shoulder and found the bottom corner of the net with unerring accuracy. Game, set and match.