Pep Guardiola turned to his bench and covered his face with his hands. If Manchester City's collapse against Feyenoord had forced him to scratch at his head, Matheus Nunes' five seconds of madness on derby day would have made him want to rip it clean off. Nunes' or his own.

City had been poor, but it was there good fortune to be playing a Manchester United side who were worse. There was little to like from the home side's performance, but with five minutes to go they were close to a morale-boosting victory that would have propelled them level with Arsenal in the Premier League table.

Then, that familiar collapse. United's toothless attack had never looked like scoring, but then this is the season for giving and City delivered a present giftwrapped and with a bow on top. Nunes' poor back pass played Amad in but Ederson had stalled him, only for Nunes to clumsily and foolishly barge into the attacker.

ALSO READ: Manchester City player ratings vs Manchester United

ALSO READ: Manchester City vs Manchester United as it happened

It was as blatant a penalty as you will see and Guardiola could not believe it. He probably could believe what came next, because it's been happening for nearly two months. Once Bruno Fernandes' penalty hit the back of the net, the collapse was about to become total.

One Lisandro Martinez pass straight down the pitch allowed Amad in behind the defence. He beat Ederson to the bounce and finished from a cute angle. City had imploded again, just as they did at Sporting and Brighton and against Feyenoord. This one will hurt more than all of those combined.

This is the kind of defeat that can torpedo a season that was already veering wildly off the rails. With five minutes to go it felt like City might be back in the title race. As their shellshocked players dragged themselves off at the end, you wondered where it will end. Nobody will fancy that trip to Villa Park now.

It's becoming a fatal flaw that this team can't hold their nerve all of a sudden, that mistakes are being made and then exacerbated by the mental collapse that follows. This was a low quality game, but one they should have won.

It was a 10-game crisis against a 10-year crisis. A side who have lost their way against a side who don't seem to know what their way actually is. It was a grim game of football, defined more by its mistakes than any moment of quality. There were 22 internationals on the pitch, but in club colours most of them toiled.

In the first half, the game got the goal it deserved. Had Ilkay Gundogan's short pass to Kevin De Bruyne had enough pace on it, then the resulting cross wouldn't have been deflected and wouldn't have looped so perfectly for Josko Gvardiol to head home.

In games like this you often hear that it will be decided by a mistake. The irony is that it was a Manchester City mistake that led to a Manchester City goal. Then it was Manchester City mistakes that led to Manchester United's goals.

Even before Nunes' catastrophic intervention, Guardiola had cut a frustrated figure, clearly not happy with what he was seeing for large periods of the game. His team again lacked creativity in attacking areas, despite the presence of De Bruyne and Phil Foden in the same starting XI for the first time this season. They had spells of control in the game, but never for extended periods.

They were also far too passive in the second half. Having got the lead, they were too tentative in trying to extend it and allowed United to stay in the contest. That proved costly. This wasn't the performance of a confident City, playing with the self-belief that used to flow through them.

Each defeat, each setback, each collapse, is seeping into the collective consciousness. They looked a wearied, beleaguered team when they left the pitch in dribs and drabs. It's eight defeats in 11, but this will sting more than most.