It was a relatively sedate 0-0 at the half-time interval when Manchester City manager Pep Guardiola changed the course of the game with two bold substitutions.

He sometimes stands accused of resisting substitutions but he was decisive here when he brought on Jack Grealish and Rico Lewis for the second half. City captain Ruben Dias was taken off, along with Savinho, and it gave a different dimension to the second half. PSG manager Luis Enrique played his part too, bringing on Ousmane Dembele for Kang-in Lee. Then mayhem ensued...

50 minutes

Grealish makes an instant impact on the left wing, lashing home a rebound after pinball in the PSG six-yard area. Gianluigi Donnarumma saves from Bernardo Silva and then keeps out a rebound off team-mate Achraf Hakimi – but Grealish fires the ball home on the volley. There is anger in the finish and the celebration. The England forward had recently ended a year-long drought without finding the net when he scored against Salford City.

53 minutes

Parc des Princes is stunned into silence when Erling Haaland makes it 2-0. He suggested that City were returning to their best when he spoke before the match and the striker, who signed a new nine-and-a-half-year contract last week, made them look like the Guardiola team of old with his far-post finish. Grealish was involved again, with his cross diverted by João Neves into Haaland’s path.

56 minutes

From silence to bedlam. The stadium erupts when PSG pull a goal back, with Dembele putting his imprint on the game with a neat finish to round off great work by Bradley Barcola. Barcola gets past Matheus Nunes and sprints towards goal, with Dembele slowing his run to pull away from his marker before slotting in the finish. There is real hope now in the stands.

60 minutes

Barcola turns the match on its head with his equaliser. He steers in the rebound after Désiré Doué hits the bar with an effort that left Ederson on the floor and not up in time for Barcola’s finish. The celebrations are wild but PSG players all run straight back to the halfway line – they sense panic in City’s back line and are chasing a winner.

78 minutes

The implosion is complete as City’s back line fall apart. Simple defending at a free-kick goes to pieces and they leave Neves unmarked at the far post. John Stones is closest too him – but not close enough – and misses his header to clear, allowing the PSG midfielder to stoop with a diving header. The hosts had their chances before this, with Dembele hitting the crossbar and Haaland surviving a decent penalty shout for handball.

90 minutes +

There is one final crazy moment to a manic second half. Goncalo Ramos, on as a sub, is behind the City defence and left alone to finish in the top corner. He looks offside and the flag goes up but VAR shows the final touch had come off Josko Gvardiol. PSG players and fans go wild when the goal is awarded – and the 4-2 victory is complete.

Pep admits: ‘If we’re knocked out, we deserve it’

Pep Guardiola admitted Manchester City would fully deserve Champions League elimination should they fail to get a result against Club Brugge next week, with the stunning defeat at Paris St-Germain leaving them in the drop zone.

City were defeated 4-2 at Parc des Princes despite going ahead through Jack Grealish and Erling Haaland. It was the ninth time Guardiola’s team have failed to hold on to a lead this season.

It left them in 25th place in the competition’s new “Swiss model” and they will be unceremoniously dumped out unless they win against Club Brugge on Wednesday, with the Belgian club currently on a 19-match unbeaten run in all competitions.

“It could happen,” said Guardiola, when asked about Champions League elimination. “If we don’t win we don’t deserve it. It’s difficult as all games are difficult but it’s reality, we didn’t get enough points and we accept it.

‘We have a last chance’

“We have a last chance against Brugge and if we don’t go through it’s because we don’t deserve it. You have to recover players and do it better.”

“Of course it is,” he added when asked if the current table was a fair reflection of the season. “It’s the points that we had. Today we didn’t deserve it. What’s the argument for fair or unfair? PSG played better in their games and couldn’t win. Today they were able to. In the big stages, the big teams, we struggle. We have to accept it. Recover and go to Chelsea on Saturday. We have to recover our game.”

Guardiola accepted that his team were second best against PSG, losing control of the midfield battle despite going 2-0 up.

“We could not control first goal. They were better, they were quicker, faster, they win the duels with the ball, one more in the middle and we could not cope with that as they were fast,” he said.

“The best team won and we have last chance at home against Brugge, hopefully we can qualify. The game was never like we wanted but I give full credit as PSG are a fantastic and extraordinary team. We could have stayed and been better with the ball but we could not do it.

“You have to play and we could not. To defend the result you have to take the ball and we didn’t have it. You have to defend better and that’s why it’s more difficult.”

Grealish fears his team-mates have lost their confidence after getting into good positions in matches.

“Usually in these moments we are so good,” he said. “It’s happened too many times this season when we’ve gone one goal or two goals up, or even three against Feyenoord, and we’ve not been able to control the game and see it out. It’s weird because in every other season we’ve been so good in these moments, managing the game.

“I don’t know if it’s a confidence thing because we know before Christmas we weren’t at the levels we know we can be. It’s down to ourselves to change that moving forward and especially to go and try to win the game next week.

“It’s difficult. I don’t know if it’s a confidence thing, we have so many players on the pitch that are so good on the ball and keeping it when we are 2-0 up but we haven’t been doing that recently and that is down to us. PSG were very energetic and a lot better than I thought – I don’t mean that in a bad way, they are a top team and deserved to win.”

Guardiola hopes that the must-win nature of next week will bring the best out of players, adding: “I hope so, we’ve had games like this in recent seasons – big-pressure games. So we’re going to need that.

“We know Brugge have had good results this season and drew against Juventus this week. It’s down to us. We are good at home, we will prepare for Chelsea and then all eyes will be on that game.”