Manchester City is the best team in the Premier League, and they came up against a Manchester United side who were upbeat after their triumph in Turin. A win would have taken City twelve points clear of United while Jose Mourinho's team had a chance to reduce it to six at the end of the weekend.
Pep Guardiola's side was on it from the word go with Bernardo Silva hitting a long-range shot, but it was off target. Manchester City got the reward for their relentless pressure with David Silva turning home from a Bernardo Silva's cross a few moments later.
After the goal, Manchester United slowed the game down and didn't allow City to play their free-flowing football. Pep Guardiola's side went into the break with their noses slightly ahead, but Jose Mourinho knew his team was still in the match.
Manchester City doubled the lead immediately into the second half with Aguero hitting a fierce shot past De Gea. However, Antony Martial pulled one back from a penalty after Ederson fouled Lukaku inside the box. The game was all done and dusted after Gundogan scored City's third goal of the day.
Here are the five takeaways from the game.
#5 Another disappointing first half from United
Jose Mourinho's side has been criticized this season for the slow start to their games and allowing the opposition to dictate the play from the word go. It's been the case for last few games now for United.
However, against Manchester City, it is always difficult to play your natural game as Pep Guardiola's side prefers to keep possession of the ball and press high up the pitch. The best way to beat City is to take the game to them as only sitting back would mean allowing City to go on a relentless attacking spree.
Manchester United struggled to get any hold in the first half with City going rampant in the first quarter of the game and breaking the deadlock through David Silva with United having all to do in the second half again.
#4 The brilliant 'Silva' combination
Manchester City fans were worried after their best player last season Kevin De Bruyne picked up an injury at the start of the season which ruled him out for several months. However, City might be the only team who doesn't suffer from the absence of their star player.
The luxury of players Pep Guardiola has got up his sleeves would make any other manager jealous. With De Bruyne out, it was time for the two Silva's - David and Bernardo to step up for the side and they didn't disappoint at all. David Silva has now scored in his last three Premier League games and has been the creator for the team as well.
Against Manchester United, David was at the heart of everything that City did, from defence-splitting passes to scoring himself after a beautiful layout by Bernardo Silva from a Raheem Sterling cross.
#3 Martial joins the rich list of stars
Antony Martial is an example of a player who got rid of personal barriers to unlock his potential as a top quality player. Last season after the arrival of Sanchez, the Frenchman's time in the starting line up was relatively cut short and he found himself mostly warming the bench.
However, Sanchez's form dipped at the start of the season, and he looked like a shadow of the player he was at Arsenal. It made United fans calling Jose Mourinho to give Antony Martial a chance to prove himself. Jose listened to the supporters call and played Martial from the left wing where he immediately flourished.
The Frenchman is in a rich vein of form at the moment and the only United player who looked like scoring whenever he has the ball. Against City, his goal from the penalty spot has put him in the same bucket of superstars like Eric Cantona, Cristiano Ronaldo, and four others who have scored five goals in five consecutive games for Manchester United.
#2 Unbeaten run continues for City
Manchester City started the game like they usually do at the Etihad stadium going all guns blazing from the very first minute. David Silva and Bernardo Silva were running the show in the midfield while Sterling and Aguero were keeping the United defence on their toes. Pep Guardiola's side should have scored more in the first half but could not increase their lead.
However, immediately after the break, Sergio Aguero doubled the lead for City with a sumptuous strike. The lead was cut to half by Antony Martial from the spot, but Gundogan's late goal all but confirmed three points for Manchester City.
The victory put Pep Guardiola side as the sole leaders on top surpassing Liverpool who won earlier in the day. They are now twelve games unbeaten and looking like the clear favourites to lift the title again this season. Etihad is becoming a fortress as no one has been able to break City at home till now.
#1 Pogba's absence felt
Paul Pogba is one of the quality players that United has got in their ranks. Last season, in this fixture, Manchester City were on the verge of winning the Premier League by beating Manchester United at the Etihad Stadium.
At the halftime, they were up by two goals until a Paul Pogba show in the second half completely changed the game around, and Manchester United walked away with all three points from that game.
However, the Frenchman's absence was deeply felt last night by Jose Mourinho and his players. There was no creativity in the middle of the pitch and Herrera made dreadful mistakes while retaining possession.
Manchester City had all the possession and dominated the entire match. With the lack of creativity, United relied upon set pieces to score, and they did that with Antony Martial scoring from the spot, but that was their only shot on target in the entire match.