Here are five things we learned as Manchester United lost 2-1 against bitter rivals Manchester City as Pep Guardiola’s side extended their lead at the top of the Premier League table to eleven points.

Lukaku struggles again

It feels disingenuous to criticise a lone striker in a game in which he was starved of service but there is no getting away from the fact that Romelu Lukaku had an absolute nightmare here.

It was only David de Gea’s heroics that prevented the Belgian from conceding an own goal when defending a set-piece away at Arsenal last week and it was the striker’s dreadful contributions from dead balls that cost United the game.

He nodded the ball towards David Silva for the game’s opening goal and his wild, aimless clearance bounced for Nicolas Otamendi to net the winner.

In a game where every other United player strained every sinew, Lukaku was off the pace. He did not protect the ball well enough, trouble makeshift centre-half Fernandinho in the early stages of the second half and was dominated in the air.

To top it all off, he missed an absolute sitter which would have levelled the match in the closing minutes, blasting straight at Ederson when a composed finish in either corner would have earned United a point.

Lukaku came to Old Trafford with question marks over his ability to contribute in the biggest games hanging over him and here he emphatically failed to deliver in the biggest match of United’s season so far. For £75m, it is not unreasonable to expect much, much more.

United couldn’t break out

Jose Mourinho’s spoiling tactics in the biggest games split opinion but it was always inevitable that the visitors would dominate possession here.

Therefore, the key was how United could turn defence into attack. This was a match in which there was more onus on the Red Devils to win than their visitors and Mourinho’s line-up reflected that – he included Lukaku, Marcus Rashford, Jesse Lingard and Anthony Martial from the off.

However, for all the pace in the attack, United’s main route out was long aimless passing, with the main culprit being Marcos Rojo before his half-time withdrawal.

The pressure became relentless because there was no way out and United, for all their efforts, were undone and exhausted as City dominated throughout, inspired by man of the match Kevin de Bruyne.

The opposition get too close to United’s area again

United tried to sit back and invite pressure before breaking but, just as against Arsenal last weekend, the end result was that City were able to get too close to the Reds’ box.

David de Gea wasn’t called into action as often as he was at the Emirates, but City could and probably should have won by more here, and the Spaniard produced a superb sprawling save to his right from de Bruyne.

Conceding too much ground meant that United were too far away from City’s goal when they got the ball, which did not allow their pacey frontline to counter and made it too easy for the visitors to press their hosts when out of possession.

United struggle from set pieces

In the build-up to the match, many observers felt one area that United could exploit was set-pieces. Especially in-swinging deliveries to the near-post as City have conceded from that area in recent matches against Huddersfield and West Ham United.

In actual fact, City won the game with two set piece goals of their own and though they were in no small part down to the putrid defensive contributions of Lukaku, this was still a shock.

Conceding both goals in such a manner will irk Mourinho, who obsesses over the smallest of details and prides himself on his team’s defensive solidity.

United contrived to lose a match via the avenue many felt would provide their biggest chance of success – which is deeply frustrating for fans and manager alike.

The title race is all but over

Giving up is not the United way and I fully expect Mourinho’s men to be City’s closest contenders as the season rumbles on.

However, United had to get something from this game to keep the title race alive, and in truth, that something really had to be a win.

City have dropped just two points all season, are eleven points clear at the Premier League’s summit, on a 14-game winning run, which included their two toughest games of the season on paper – away clashes against United and reigning champions Chelsea.

They have ground out four consecutive 2-1 wins, and the fact that they are marrying steel with their attacking brand of football is ominous for United and the rest of the league.

United have staged some incredible comebacks in Premier League title races down the years but clawing their way into contention and lifting the crown this time around would top the lot.