Ruben Dias suddenly remembers Enzo Maresca's strict rule during wild Man City celebrations

Manchester City captain Ruben Dias forgot to follow Enzo Maresca's golden rule after the controversial derby winner scored by Erling Haaland on Sunday.

City, who had 10 men for 60 minutes after Phil Foden was sent off for reacting to Bruno Fernandes, came away with a hard-fought 1-0 win at Old Trafford after Haaland popped up in the second half.

The Norwegian's strike was initially ruled out but a VAR review showed that he was in an onside position.

The goal was then given despite Enzo Fernandez attempting to head the ball while in an offside position in the build-up.

Pro Ref would go on to issue a statement confirming the decision to award the goal was wrong.

What Ruben Dias did after Man City's winner against Man United

Haaland was confident he was onside and began preparing to celebrate his ninth goal in a Manchester derby.

READ MORE: New footage of Bruno Fernandes emerges moments before Phil Foden's controversial Man City red card

City players erupted in front of the away end but skipper Dias had a key role. Footage which emerged online showed that while the Portugal international initially sprinted to join his teammates, he then changed his route.

Instead of embracing all his colleagues, Dias received vital tactical instructions on the touchline from Maresca.

Dias was named Maresca's captain following the departure of compatriot Bernardo Silva, with Marc Guehi, Gianluigi Donnarumma and Haaland featuring in the leadership group.

As part of his responsibilities, Dias must head over to Maresca every time City score to take in information and pass it on to his teammates.

In the excitement of a derby goal, he did briefly forget before realising. But it is a rule Maresca enforced during his time at Leicester and Chelsea before implementing it in City's pre-season.

Speaking to journalists in Seoul, he said, "I think even if it is two or three minutes in, there is always something to adjust".

Maresca did explain that Dias is only exempt from the instructions if he scores as he noted the difficulty if Haaland is wearing the armband.

He joked: "But if the captain scores, then he can celebrate. If Erling is the captain, f****** hell, we have a problem. Can you imagine?"

Enzo Maresca reveals what he told Ruben Dias in key Manchester derby instruction

City performed better with 10 men after Foden's red card and the half-time introduction of Iliman Ndiaye allowed them to get up the pitch much quicker.

City were able to frustrate United and limit their transitions, whilst also carrying a major threat when they had the ball.

READ MORE: Joe Hart is going viral for his take on Erling Haaland's controversial goal in the Manchester derby

Dias was in conversation with Maresca following the goal and the Italian revealed that his message involving handling Fernandes and limiting his involvement.

"Straight after the goal it was so important to manage those five minutes and to continue in the same way," he told ViaPlay.

"I just said to Ruben that we need one player with Bruno.

"So when Enzo was inside the pitch, when we were with 10 players, was in charge of Bruno.

"And then when Nico, he was - just because he's the main player for them."

City have won every game under Maresca since the Community Shield loss to Arsenal and are back in action on Thursday when they take on Norwich in the Carabao Cup.

Their next Premier League game is the visit of Sunderland on Sunday.