On Sunday, goals from Ashley Young, Marouane Fellaini, Juan Mata and Chris Smalling were more than enough to cancel out a brace from Sergio Aguero as Manchester United thoroughly outplayed Manchester City on their way to a 4-2 derby day victory. City began the game in the ascendency before Aguero opened the scoring in the 8th minute. However, United responded immediately and upped their game as they scored four unanswered goals before Aguero pulled back a late consolation. Let's take a look at five things we learned from this match...

Manchester Is Red

Although this is the most obvious takeaway, the victory for United today seemed to be worth more than just three points. City had won the previous four derbies and six of the last seven in addition to two of the last three titles. When that was coupled with United's horrible season last term, it appeared the balance of power in Manchester had shifted. However, City have struggled all season long and United are now four points ahead of their noisy neighbours. The Blues have lost six of their last eight matches in all competitions, and appear to be in danger of missing out on a Champions League place. United are now undoubtedly number one in Manchester, and could be for quite some time to come.

David Moyes may not have known how to manage United, but he signed the right players

Marouane Fellaini for so long was the symbol of David Moyes' failed reign. However, under Louis Van Gaal he has blossomed into a player his manager calls "undroppable". This season, he's been employed as a deep lying target man and on Sunday was arguably the man of the match. He made Yaya Toure a non-factor in the centre of the park, and didn't allow City to pass the ball the way the normally do. Additionally, it was his head that put United ahead for good. 

Another of United's star performers on the day was Juan Mata. Mata, signed last winter as a player many derided as a morale building signing rather than one who added anything to the squad. This season, he struggled to consistently get into the team until several weeks ago. However, when he scored a brace at Anfield three weeks ago he confirmed his new status as another undroppable player. The man now called a "false winger" by the press is again proving that Moyes knew what he was doing when signing players.

Manchester City are in danger of losing their place at the top table

City are still the defending champions and made it into the knockout stages of the UEFA Champions League this year, but they are now in danger of missing out on the Champions League next season. With Sunday's defeat, they fell four points behind United in the table and have just a five point lead on Southampton in fifth place. Liverpool, sitting in sixth, play on Monday night and a victory for the Anfield side would bring them within four points. City have now lost six of their last eight, and unless they can halt this slide may not finish in the top four.

Ashley Young is the most underrated player in the Barclays Premier League

On the American television broadcast on Sunday, play-by-play commentator Arlo White remarked that he finds Ashley Young to be the most underrated player in the Premier League. That is a bold statement to make, and one that this writer agrees with. In Young's last 16 Premier League starts, United are 11-5-0. He works incredibly hard off the ball for his team, tracks back defensively and has developed a terrific understanding with Daley Blind down the left wing. On Sunday, all of his talents came to the fore as he scored United's equaliser before setting up Fellaini's and Smalling's goals. Louis Van Gaal has finally found a winning formula with United, and Young is a crucial component of it.

Yaya Toure should take the bumper pay packet from Inter Milan

There have been all sorts of rumours swirling around about Yaya Toure's future, and the consensus seems to be that Inter Milan are desperate to have him. On the basis of Sunday's performance, City may be willing to sell. Toure was anonymous for the entire 90 minutes, and made Marouane Fellaini look like a world class midfielder. This was undoubtedly Toure's worst performance in a blue shirt for quite some time, and if there's another team which will sign him and pay what he's making now, he should take that chance.