Manchester United boss Louis van Gaal has hailed his side's performance in their 4-2 victory over Manchester City in their derby clash at Old Trafford.

Sergio Aguero put Manuel Pellegrini's men ahead in the eighth minute, but United responded quickly through Ashley Young and Marouane Fellaini edged the home side ahead before half time.

Juan Mata put the Red Devils in control of the game as he added a third midway through the second half and Chris Smalling ensured the victory, despite a late consolation goal from Aguero.

Van Gaal told Sky Sports News: "It's three points. We are four points ahead of fourth in the table and I am very happy for the fans. I have seen what it means for them. They always support us when the results were not good.

"It's the best atmosphere I have seen here. A fantastic result. I must bring Michael Carrick off the pitch with an injury which was a bit stupid from me as some players didn't know we only had 10 men. That was not so smart!

"We started very badly. It was not Manchester United, we were very nervous. I don't know why. We had no pressure on the ball. I don't know why. But when we scored the goal, from that moment we had more confidence. The second half was much better."

United are third in the Premier League on 65 points, leaving them eight points clear of Southampton in fifth place in the race for the Champions League.