Goals from Sergio Aguero and Yaya Toure have given Manchester City a 2-0 half-time lead over Manchester United at the Etihad Stadium in the Premier League.
Aguero put his side ahead in the 16th minute with a superb left-footed volley following good work by Samir Nasri and Alexander Kolarov.
City continued to dominate proceedings and Nasri came close to scoring himself with a rasping volley from 18 yards.
Referee Howard Webb waved away Man City's claims for a penalty when Kolarov collided with Chris Smalling in the box and Wayne Rooney earned a booking as tempers flared.
In first-half stoppage time, Toure reacted first to deflect Alvaro Negredo's effort into the net off his knee.